svn commit: r44163 - head/en_US.ISO8859-1/books/handbook/advanced-networking
Dru Lavigne
dru at FreeBSD.org
Thu Mar 6 23:27:25 UTC 2014
Author: dru
Date: Thu Mar 6 23:27:25 2014
New Revision: 44163
URL: http://svnweb.freebsd.org/changeset/doc/44163
Log:
White space fix only. Translators can ignore.
Sponsored by: iXsystems
Modified:
head/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.xml
Modified: head/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.xml
==============================================================================
--- head/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.xml Thu Mar 6 23:00:13 2014 (r44162)
+++ head/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.xml Thu Mar 6 23:27:25 2014 (r44163)
@@ -2848,104 +2848,106 @@ rfcomm_sppd[94692]: Starting on /dev/tty
<primary>bridge</primary>
</indexterm>
- <para>It is sometimes useful to divide a network,
- such as an Ethernet segment, into network
- segments without having to create <acronym>IP</acronym>
- subnets and use a router to connect the segments together.
- A device that connects two networks together in this fashion
- is called a <quote>bridge</quote>.</para>
-
- <para>A bridge works by learning the <acronym>MAC</acronym>
- addresses of the devices on each of its
- network interfaces. It forwards traffic between networks
- only when the source and destination <acronym>MAC</acronym> addresses are on different
- networks. In many respects, a bridge is like an Ethernet switch with
- very few ports. A &os; system with multiple
- network interfaces can be configured to act as a bridge.</para>
+ <para>It is sometimes useful to divide a network, such as an
+ Ethernet segment, into network segments without having to
+ create <acronym>IP</acronym> subnets and use a router to connect
+ the segments together. A device that connects two networks
+ together in this fashion is called a
+ <quote>bridge</quote>.</para>
+
+ <para>A bridge works by learning the <acronym>MAC</acronym>
+ addresses of the devices on each of its network interfaces. It
+ forwards traffic between networks only when the source and
+ destination <acronym>MAC</acronym> addresses are on different
+ networks. In many respects, a bridge is like an Ethernet switch
+ with very few ports. A &os; system with multiple network
+ interfaces can be configured to act as a bridge.</para>
- <para>Bridging can be useful in the following situations:</para>
+ <para>Bridging can be useful in the following situations:</para>
- <variablelist>
- <varlistentry>
+ <variablelist>
+ <varlistentry>
<term>Connecting Networks</term>
<listitem>
- <para>The basic operation of a bridge is to join two or more
- network segments. There are many reasons to use a
- host-based bridge instead of networking equipment, such as
- cabling constraints or firewalling. A bridge can
- also connect a wireless interface running in hostap mode to
- a wired network and act as an access point.</para>
- </listitem>
- </varlistentry>
+ <para>The basic operation of a bridge is to join two or more
+ network segments. There are many reasons to use a
+ host-based bridge instead of networking equipment, such as
+ cabling constraints or firewalling. A bridge can also
+ connect a wireless interface running in hostap mode to a
+ wired network and act as an access point.</para>
+ </listitem>
+ </varlistentry>
- <varlistentry>
+ <varlistentry>
<term>Filtering/Traffic Shaping Firewall</term>
<listitem>
- <para>A bridge can be used when firewall functionality is
- needed without routing or Network Address Translation
- (<acronym>NAT</acronym>).</para>
-
- <para>An example is a small company that is connected via
- <acronym>DSL</acronym>
- or <acronym>ISDN</acronym> to an <acronym>ISP</acronym>.
- There are thirteen public <acronym>IP</acronym>
- addresses from the <acronym>ISP</acronym> and ten computers
- on the network. In this situation, using a router-based
- firewall is difficult because of subnetting issues. A bridge-based firewall can be configured without any
- <acronym>IP</acronym> addressing issues.</para>
- </listitem>
- </varlistentry>
+ <para>A bridge can be used when firewall functionality is
+ needed without routing or Network Address Translation
+ (<acronym>NAT</acronym>).</para>
+
+ <para>An example is a small company that is connected via
+ <acronym>DSL</acronym> or <acronym>ISDN</acronym> to an
+ <acronym>ISP</acronym>. There are thirteen public
+ <acronym>IP</acronym> addresses from the
+ <acronym>ISP</acronym> and ten computers on the network.
+ In this situation, using a router-based firewall is
+ difficult because of subnetting issues. A bridge-based
+ firewall can be configured without any
+ <acronym>IP</acronym> addressing issues.</para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term>Network Tap</term>
<listitem>
- <para>A bridge can join two network segments in order to
- inspect all Ethernet frames that pass between them using
- &man.bpf.4; and &man.tcpdump.1; on the bridge interface or
- by sending a copy of all frames out an additional interface
- known as a span port.</para>
- </listitem>
- </varlistentry>
+ <para>A bridge can join two network segments in order to
+ inspect all Ethernet frames that pass between them using
+ &man.bpf.4; and &man.tcpdump.1; on the bridge interface or
+ by sending a copy of all frames out an additional
+ interface known as a span port.</para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term>Layer 2 <acronym>VPN</acronym></term>
<listitem>
- <para>Two Ethernet networks can be joined across an
- <acronym>IP</acronym> link by bridging the networks to an
- EtherIP tunnel or a &man.tap.4; based solution such as
- <application>OpenVPN</application>.</para>
- </listitem>
- </varlistentry>
+ <para>Two Ethernet networks can be joined across an
+ <acronym>IP</acronym> link by bridging the networks to an
+ EtherIP tunnel or a &man.tap.4; based solution such as
+ <application>OpenVPN</application>.</para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term>Layer 2 Redundancy</term>
<listitem>
- <para>A network can be connected together with multiple links
- and use the Spanning Tree Protocol (<acronym>STP</acronym>)
- to block redundant paths.</para>
- </listitem>
- </varlistentry>
- </variablelist>
+ <para>A network can be connected together with multiple
+ links and use the Spanning Tree Protocol
+ (<acronym>STP</acronym>) to block redundant paths.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
- <para>This section describes how to configure a &os; system as a
- bridge using &man.if.bridge.4;.
- A netgraph bridging driver is also available, and is described
- in &man.ng.bridge.4;.</para>
+ <para>This section describes how to configure a &os; system as a
+ bridge using &man.if.bridge.4;. A netgraph bridging driver is
+ also available, and is described in &man.ng.bridge.4;.</para>
- <note>
+ <note>
<para>Packet filtering can be used with any firewall package
- that hooks into the &man.pfil.9; framework. The bridge can be used as a traffic shaper with
- &man.altq.4; or &man.dummynet.4;.</para>
- </note>
+ that hooks into the &man.pfil.9; framework. The bridge can be
+ used as a traffic shaper with &man.altq.4; or
+ &man.dummynet.4;.</para>
+ </note>
<sect2>
<title>Enabling the Bridge</title>
<para>In &os;, &man.if.bridge.4; is a kernel module which is
automatically loaded by &man.ifconfig.8; when creating a
- bridge interface. It is also possible to compile bridge support
- into a custom kernel by adding <literal>device if_bridge</literal>
- to the custom kernel configuration file.</para>
+ bridge interface. It is also possible to compile bridge
+ support into a custom kernel by adding
+ <literal>device if_bridge</literal> to the custom kernel
+ configuration file.</para>
<para>The bridge is created using interface cloning. To create
the bridge interface:</para>
@@ -2968,19 +2970,18 @@ bridge0: flags=8802<BROADCAST,SIMPLEX
The other parameters control how <acronym>STP</acronym>
operates.</para>
- <para>Next, specify which network interfaces to add as members of the bridge.
- For the bridge to forward packets, all member interfaces and
- the bridge need to be up:</para>
+ <para>Next, specify which network interfaces to add as members
+ of the bridge. For the bridge to forward packets, all member
+ interfaces and the bridge need to be up:</para>
<screen>&prompt.root; <userinput>ifconfig bridge0 addm fxp0 addm fxp1 up</userinput>
&prompt.root; <userinput>ifconfig fxp0 up</userinput>
&prompt.root; <userinput>ifconfig fxp1 up</userinput></screen>
<para>The bridge can now forward Ethernet frames between
- <filename>fxp0</filename> and
- <filename>fxp1</filename>. Add the following lines to
- <filename>/etc/rc.conf</filename> so the bridge is created
- at startup:</para>
+ <filename>fxp0</filename> and <filename>fxp1</filename>. Add
+ the following lines to <filename>/etc/rc.conf</filename> so
+ the bridge is created at startup:</para>
<programlisting>cloned_interfaces="bridge0"
ifconfig_bridge0="addm fxp0 addm fxp1 up"
@@ -2988,9 +2989,8 @@ ifconfig_fxp0="up"
ifconfig_fxp1="up"</programlisting>
<para>If the bridge host needs an <acronym>IP</acronym>
- address, set it on the bridge
- interface, not on the member interfaces.
- The address can be set statically or via
+ address, set it on the bridge interface, not on the member
+ interfaces. The address can be set statically or via
<acronym>DHCP</acronym>. This example sets a static
<acronym>IP</acronym> address:</para>
@@ -3002,48 +3002,44 @@ ifconfig_fxp1="up"</programlisting>
<filename>/etc/rc.conf</filename>.</para>
<note>
- <para>When packet filtering is enabled, bridged packets will
- pass through the filter inbound on the originating interface
- on the bridge interface, and outbound on the appropriate
- interfaces. Either stage can be disabled. When direction of
- the packet flow is important, it is best to firewall on the
- member interfaces rather than the bridge itself.</para>
-
- <para>The bridge has several configurable settings for passing
- non-<acronym>IP</acronym> and <acronym>IP</acronym> packets,
- and layer2 firewalling with &man.ipfw.8;. See
- &man.if.bridge.4; for more information.</para>
+ <para>When packet filtering is enabled, bridged packets will
+ pass through the filter inbound on the originating interface
+ on the bridge interface, and outbound on the appropriate
+ interfaces. Either stage can be disabled. When direction
+ of the packet flow is important, it is best to firewall on
+ the member interfaces rather than the bridge itself.</para>
+
+ <para>The bridge has several configurable settings for passing
+ non-<acronym>IP</acronym> and <acronym>IP</acronym> packets,
+ and layer2 firewalling with &man.ipfw.8;. See
+ &man.if.bridge.4; for more information.</para>
</note>
</sect2>
<sect2>
<title>Enabling Spanning Tree</title>
- <para>For an Ethernet network to
- function properly, only one active path can exist between
- two devices. The <acronym>STP</acronym> protocol detects loops and
- puts redundant links into a blocked state. Should one
- of the active links fail, <acronym>STP</acronym>
- calculates a different tree and enables one of the blocked
- paths to restore connectivity to all points in the
- network.</para>
-
- <para>The Rapid Spanning Tree
- Protocol (<acronym>RSTP</acronym> or 802.1w) provides backwards
- compatibility with legacy <acronym>STP</acronym>.
- <acronym>RSTP</acronym> provides
- faster convergence and
- exchanges information with neighboring switches
- to quickly transition to forwarding mode without creating loops.
- &os; supports <acronym>RSTP</acronym> and
+ <para>For an Ethernet network to function properly, only one
+ active path can exist between two devices. The
+ <acronym>STP</acronym> protocol detects loops and puts
+ redundant links into a blocked state. Should one of the
+ active links fail, <acronym>STP</acronym> calculates a
+ different tree and enables one of the blocked paths to restore
+ connectivity to all points in the network.</para>
+
+ <para>The Rapid Spanning Tree Protocol (<acronym>RSTP</acronym>
+ or 802.1w) provides backwards compatibility with legacy
+ <acronym>STP</acronym>. <acronym>RSTP</acronym> provides
+ faster convergence and exchanges information with neighboring
+ switches to quickly transition to forwarding mode without
+ creating loops. &os; supports <acronym>RSTP</acronym> and
<acronym>STP</acronym> as operating modes, with
<acronym>RSTP</acronym> being the default mode.</para>
<para><acronym>STP</acronym> can be enabled on member interfaces
using &man.ifconfig.8;. For a bridge with
- <filename>fxp0</filename> and
- <filename>fxp1</filename> as the current interfaces,
- enable <acronym>STP</acronym> with:</para>
+ <filename>fxp0</filename> and <filename>fxp1</filename> as the
+ current interfaces, enable <acronym>STP</acronym> with:</para>
<screen>&prompt.root; <userinput>ifconfig bridge0 stp fxp0 stp fxp1</userinput>
bridge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
@@ -3088,163 +3084,163 @@ bridge0: flags=8843<UP,BROADCAST,RUNN
</sect2>
<sect2>
- <title>Bridge Interface Parameters</title>
+ <title>Bridge Interface Parameters</title>
- <para>Several <command>ifconfig</command> parameters are unique
- to bridge interfaces. This section summarizes some common
- uses for these parameters. The complete list of available parameters is
- described in &man.ifconfig.8;.</para>
-
- <variablelist>
- <varlistentry>
- <term>private</term>
- <listitem>
- <para>A private interface does not forward any traffic to any
- other port that is also designated as a private interface. The traffic is
- blocked unconditionally so no Ethernet frames will be
- forwarded, including <acronym>ARP</acronym> packets. If traffic
- needs to be selectively blocked, a firewall should be used
- instead.</para>
- </listitem>
- </varlistentry>
+ <para>Several <command>ifconfig</command> parameters are unique
+ to bridge interfaces. This section summarizes some common
+ uses for these parameters. The complete list of available
+ parameters is described in &man.ifconfig.8;.</para>
- <varlistentry>
- <term>span</term>
- <listitem>
- <para>A span port transmits a copy of every Ethernet frame received by the bridge.
- The number
- of span ports configured on a bridge is unlimited, but if an
- interface is designated as a span port, it cannot also be
- used as a regular bridge port. This is most useful for
- snooping a bridged network passively on another host
- connected to one of the span ports of the bridge. For
- example, to send a copy of all frames out the interface named
- <filename>fxp4</filename>:</para>
+ <variablelist>
+ <varlistentry>
+ <term>private</term>
+ <listitem>
+ <para>A private interface does not forward any traffic to
+ any other port that is also designated as a private
+ interface. The traffic is blocked unconditionally so no
+ Ethernet frames will be forwarded, including
+ <acronym>ARP</acronym> packets. If traffic needs to be
+ selectively blocked, a firewall should be used
+ instead.</para>
+ </listitem>
+ </varlistentry>
- <screen>&prompt.root; <userinput>ifconfig bridge0 span fxp4</userinput></screen>
- </listitem>
- </varlistentry>
+ <varlistentry>
+ <term>span</term>
+ <listitem>
+ <para>A span port transmits a copy of every Ethernet frame
+ received by the bridge. The number of span ports
+ configured on a bridge is unlimited, but if an
+ interface is designated as a span port, it cannot also
+ be used as a regular bridge port. This is most useful
+ for snooping a bridged network passively on another host
+ connected to one of the span ports of the bridge. For
+ example, to send a copy of all frames out the interface
+ named <filename>fxp4</filename>:</para>
+
+ <screen>&prompt.root; <userinput>ifconfig bridge0 span fxp4</userinput></screen>
+ </listitem>
+ </varlistentry>
- <varlistentry>
- <term>sticky</term>
- <listitem>
- <para>If a bridge member interface is marked as sticky,
- dynamically learned address entries are treated at static
- entries in the forwarding cache. Sticky entries are
- never aged out of the cache or replaced, even if the address
- is seen on a different interface. This gives the benefit of
- static address entries without the need to pre-populate the
- forwarding table. Clients learned on a particular segment
- of the bridge can not roam to another segment.</para>
-
- <para>An example of using sticky addresses is to combine
- the bridge with <acronym>VLAN</acronym>s in order to isolate
- customer networks without wasting
- <acronym>IP</acronym> address space. Consider that
- <systemitem class="fqdomainname">CustomerA</systemitem> is
- on <literal>vlan100</literal>, <systemitem
- class="fqdomainname">CustomerB</systemitem> is on
- <literal>vlan101</literal>, and the bridge has the address
- <systemitem class="ipaddress">192.168.0.1</systemitem>:</para>
+ <varlistentry>
+ <term>sticky</term>
+ <listitem>
+ <para>If a bridge member interface is marked as sticky,
+ dynamically learned address entries are treated at
+ static entries in the forwarding cache. Sticky entries
+ are never aged out of the cache or replaced, even if the
+ address is seen on a different interface. This gives
+ the benefit of static address entries without the need
+ to pre-populate the forwarding table. Clients learned
+ on a particular segment of the bridge can not roam to
+ another segment.</para>
+
+ <para>An example of using sticky addresses is to combine
+ the bridge with <acronym>VLAN</acronym>s in order to
+ isolate customer networks without wasting
+ <acronym>IP</acronym> address space. Consider that
+ <systemitem class="fqdomainname">CustomerA</systemitem>
+ is on <literal>vlan100</literal>, <systemitem
+ class="fqdomainname">CustomerB</systemitem> is on
+ <literal>vlan101</literal>, and the bridge has the
+ address <systemitem
+ class="ipaddress">192.168.0.1</systemitem>:</para>
- <screen>&prompt.root; <userinput>ifconfig bridge0 addm vlan100 sticky vlan100 addm vlan101 sticky vlan101</userinput>
+ <screen>&prompt.root; <userinput>ifconfig bridge0 addm vlan100 sticky vlan100 addm vlan101 sticky vlan101</userinput>
&prompt.root; <userinput>ifconfig bridge0 inet 192.168.0.1/24</userinput></screen>
- <para>In this example, both clients see <systemitem
- class="ipaddress">192.168.0.1</systemitem> as their
- default gateway. Since the bridge cache is sticky, one host
- can not spoof the <acronym>MAC</acronym> address of the
- other customer in order to intercept their traffic.</para>
-
- <para>Any communication between the <acronym>VLAN</acronym>s
- can be blocked using a firewall or, as seen in this example,
- private interfaces:</para>
-
- <screen>&prompt.root; <userinput>ifconfig bridge0 private vlan100 private vlan101</userinput></screen>
-
- <para>The customers are completely isolated from each other
- and the full <systemitem class="netmask">/24</systemitem>
- address range can be allocated without subnetting.</para>
-
- <para>The number of unique source <acronym>MAC</acronym>
- addresses behind an interface can be limited. Once the
- limit is reached, packets with unknown source addresses
- are dropped until an existing host cache entry expires or
- is removed.</para>
-
- <para>The following example sets the maximum number of
- Ethernet devices for <systemitem
- class="fqdomainname">CustomerA</systemitem> on
- <literal>vlan100</literal> to 10:</para>
+ <para>In this example, both clients see <systemitem
+ class="ipaddress">192.168.0.1</systemitem> as their
+ default gateway. Since the bridge cache is sticky, one
+ host can not spoof the <acronym>MAC</acronym> address of
+ the other customer in order to intercept their
+ traffic.</para>
+
+ <para>Any communication between the
+ <acronym>VLAN</acronym>s can be blocked using a firewall
+ or, as seen in this example, private interfaces:</para>
+
+ <screen>&prompt.root; <userinput>ifconfig bridge0 private vlan100 private vlan101</userinput></screen>
+
+ <para>The customers are completely isolated from each
+ other and the full <systemitem
+ class="netmask">/24</systemitem> address range can be
+ allocated without subnetting.</para>
+
+ <para>The number of unique source <acronym>MAC</acronym>
+ addresses behind an interface can be limited. Once the
+ limit is reached, packets with unknown source addresses
+ are dropped until an existing host cache entry expires
+ or is removed.</para>
+
+ <para>The following example sets the maximum number of
+ Ethernet devices for <systemitem
+ class="fqdomainname">CustomerA</systemitem> on
+ <literal>vlan100</literal> to 10:</para>
+
+ <screen>&prompt.root; <userinput>ifconfig bridge0 ifmaxaddr vlan100 10</userinput></screen>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+
+ <para>Bridge interfaces also support monitor mode, where the
+ packets are discarded after &man.bpf.4; processing and are not
+ processed or forwarded further. This can be used to
+ multiplex the input of two or more interfaces into a single
+ &man.bpf.4; stream. This is useful for reconstructing the
+ traffic for network taps that transmit the RX/TX signals out
+ through two separate interfaces. For example, to read the
+ input from four network interfaces as one stream:</para>
- <screen>&prompt.root; <userinput>ifconfig bridge0 ifmaxaddr vlan100 10</userinput></screen>
- </listitem>
- </varlistentry>
- </variablelist>
-
- <para>Bridge interfaces also support monitor mode, where the packets are
- discarded after &man.bpf.4; processing and are not
- processed or forwarded further. This can be used to
- multiplex the input of two or more interfaces into a single
- &man.bpf.4; stream. This is useful for reconstructing the
- traffic for network taps that transmit the RX/TX signals out
- through two separate interfaces. For example,
- to read the input from four network interfaces as one
- stream:</para>
-
- <screen>&prompt.root; <userinput>ifconfig bridge0 addm fxp0 addm fxp1 addm fxp2 addm fxp3 monitor up</userinput>
-&prompt.root; <userinput>tcpdump -i bridge0</userinput></screen>
-</sect2>
+ <screen>&prompt.root; <userinput>ifconfig bridge0 addm fxp0 addm fxp1 addm fxp2 addm fxp3 monitor up</userinput>
+&prompt.root; <userinput>tcpdump -i bridge0</userinput></screen>
+ </sect2>
- <sect2>
- <title><acronym>SNMP</acronym> Monitoring</title>
+ <sect2>
+ <title><acronym>SNMP</acronym> Monitoring</title>
- <para>The bridge interface and <acronym>STP</acronym>
- parameters can be monitored via &man.bsnmpd.1; which is
- included in the &os; base system. The exported bridge
- <acronym>MIB</acronym>s conform to
- <acronym>IETF</acronym> standards so any
- <acronym>SNMP</acronym> client or monitoring package can be
- used to retrieve the data.</para>
-
- <para>To enable monitoring on the bridge, uncomment this
- line in
- <filename>/etc/snmp.config</filename> by removing the
- beginning <literal>#</literal> symbol:</para>
-
- <programlisting>begemotSnmpdModulePath."bridge" = "/usr/lib/snmp_bridge.so"</programlisting>
-
- <para>Other configuration settings, such as community
- names and access lists, may need to be modified in this file. See
- &man.bsnmpd.1; and &man.snmp.bridge.3; for more
- information. Once these edits are saved, add this line to
- <filename>/etc/rc.conf</filename>:</para>
-
- <programlisting>bsnmpd_enable="YES"</programlisting>
-
- <para>Then, start
- &man.bsnmpd.1;:</para>
+ <para>The bridge interface and <acronym>STP</acronym>
+ parameters can be monitored via &man.bsnmpd.1; which is
+ included in the &os; base system. The exported bridge
+ <acronym>MIB</acronym>s conform to <acronym>IETF</acronym>
+ standards so any <acronym>SNMP</acronym> client or monitoring
+ package can be used to retrieve the data.</para>
+
+ <para>To enable monitoring on the bridge, uncomment this line in
+ <filename>/etc/snmp.config</filename> by removing the
+ beginning <literal>#</literal> symbol:</para>
+
+ <programlisting>begemotSnmpdModulePath."bridge" = "/usr/lib/snmp_bridge.so"</programlisting>
- <screen>&prompt.root; <userinput>service bsnmpd start</userinput></screen>
+ <para>Other configuration settings, such as community names and
+ access lists, may need to be modified in this file. See
+ &man.bsnmpd.1; and &man.snmp.bridge.3; for more information.
+ Once these edits are saved, add this line to
+ <filename>/etc/rc.conf</filename>:</para>
+
+ <programlisting>bsnmpd_enable="YES"</programlisting>
+
+ <para>Then, start &man.bsnmpd.1;:</para>
+
+ <screen>&prompt.root; <userinput>service bsnmpd start</userinput></screen>
- <para>The following examples use the
- <application>Net-SNMP</application> software
- (<package>net-mgmt/net-snmp</package>) to query a bridge
- from a client system. The
- <package>net-mgmt/bsnmptools</package> port can also be
- used. From the <acronym>SNMP</acronym> client which is
- running <application>Net-SNMP</application>, add the
- following lines to
- <filename>$HOME/.snmp/snmp.conf</filename> in order to
- import the bridge <acronym>MIB</acronym> definitions:</para>
+ <para>The following examples use the
+ <application>Net-SNMP</application> software
+ (<package>net-mgmt/net-snmp</package>) to query a bridge
+ from a client system. The
+ <package>net-mgmt/bsnmptools</package> port can also be used.
+ From the <acronym>SNMP</acronym> client which is running
+ <application>Net-SNMP</application>, add the following lines
+ to <filename>$HOME/.snmp/snmp.conf</filename> in order to
+ import the bridge <acronym>MIB</acronym> definitions:</para>
- <programlisting>mibdirs +/usr/share/snmp/mibs
+ <programlisting>mibdirs +/usr/share/snmp/mibs
mibs +BRIDGE-MIB:RSTP-MIB:BEGEMOT-MIB:BEGEMOT-BRIDGE-MIB</programlisting>
- <para>To monitor a single bridge using the IETF BRIDGE-MIB
- (RFC4188):</para>
+ <para>To monitor a single bridge using the IETF BRIDGE-MIB
+ (RFC4188):</para>
- <screen>&prompt.user; <userinput>snmpwalk -v 2c -c public bridge1.example.com mib-2.dot1dBridge</userinput>
+ <screen>&prompt.user; <userinput>snmpwalk -v 2c -c public bridge1.example.com mib-2.dot1dBridge</userinput>
BRIDGE-MIB::dot1dBaseBridgeAddress.0 = STRING: 66:fb:9b:6e:5c:44
BRIDGE-MIB::dot1dBaseNumPorts.0 = INTEGER: 1 ports
BRIDGE-MIB::dot1dStpTimeSinceTopologyChange.0 = Timeticks: (189959) 0:31:39.59 centi-seconds
@@ -3261,18 +3257,18 @@ BRIDGE-MIB::dot1dStpPortDesignatedPort.3
BRIDGE-MIB::dot1dStpPortForwardTransitions.3 = Counter32: 1
RSTP-MIB::dot1dStpVersion.0 = INTEGER: rstp(2)</screen>
- <para>The <literal>dot1dStpTopChanges.0</literal> value is
- two, indicating that the <acronym>STP</acronym> bridge
- topology has changed twice. A topology change means that
- one or more links in the network have changed or failed
- and a new tree has been calculated. The
- <literal>dot1dStpTimeSinceTopologyChange.0</literal> value
- will show when this happened.</para>
+ <para>The <literal>dot1dStpTopChanges.0</literal> value is two,
+ indicating that the <acronym>STP</acronym> bridge topology has
+ changed twice. A topology change means that one or more links
+ in the network have changed or failed and a new tree has been
+ calculated. The
+ <literal>dot1dStpTimeSinceTopologyChange.0</literal> value
+ will show when this happened.</para>
- <para>To monitor multiple bridge interfaces, the private
- BEGEMOT-BRIDGE-MIB can be used:</para>
+ <para>To monitor multiple bridge interfaces, the private
+ BEGEMOT-BRIDGE-MIB can be used:</para>
- <screen>&prompt.user; <userinput>snmpwalk -v 2c -c public bridge1.example.com</userinput>
+ <screen>&prompt.user; <userinput>snmpwalk -v 2c -c public bridge1.example.com</userinput>
enterprises.fokus.begemot.begemotBridge
BEGEMOT-BRIDGE-MIB::begemotBridgeBaseName."bridge0" = STRING: bridge0
BEGEMOT-BRIDGE-MIB::begemotBridgeBaseName."bridge2" = STRING: bridge2
@@ -3288,10 +3284,10 @@ BEGEMOT-BRIDGE-MIB::begemotBridgeStpTopC
BEGEMOT-BRIDGE-MIB::begemotBridgeStpDesignatedRoot."bridge0" = Hex-STRING: 80 00 00 40 95 30 5E 31
BEGEMOT-BRIDGE-MIB::begemotBridgeStpDesignatedRoot."bridge2" = Hex-STRING: 80 00 00 50 8B B8 C6 A9</screen>
- <para>To change the bridge interface being monitored via the
- <literal>mib-2.dot1dBridge</literal> subtree:</para>
+ <para>To change the bridge interface being monitored via the
+ <literal>mib-2.dot1dBridge</literal> subtree:</para>
- <screen>&prompt.user; <userinput>snmpset -v 2c -c private bridge1.example.com</userinput>
+ <screen>&prompt.user; <userinput>snmpset -v 2c -c private bridge1.example.com</userinput>
BEGEMOT-BRIDGE-MIB::begemotBridgeDefaultBridgeIf.0 s bridge2</screen>
</sect2>
</sect1>
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