VMNET - problem with epair in jail, cannot ping itself?
Palle Girgensohn
girgen at FreeBSD.org
Mon Mar 19 08:04:46 UTC 2012
Nikos Vassiliadis skrev:
> On 3/19/2012 12:47 AM, Palle Girgensohn wrote:
>> Hi!
>>
>> When I create an epair and pu one end inside a jail, and give that
>> interface an IP address, the jail still seems to want to use the lo0
>> interface to route traffic to that interface on the inside.
>>
>> Everything else works, I can set up bridges just like it would be an
>> ethernet switch, add services on the inside, it is all fine, except this
>> little annoying bug(?).
>>
>> See here:
>>
>> [root at hostname /home/girgen]# ifconfig epair create
>> epair0a
>> [root at hostname /home/girgen]# jail -c vnet name=bar host.hostname=bar
>> path=/ persist
>> [root at hostname /home/girgen]# jls
>> JID IP Address Hostname Path
>> 1 - bar /
>> [root at hostname /home/girgen]# ifconfig epair0b vnet bar
>> [root at hostname /home/girgen]# ifconfig -a
>> bce0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu
>> 1500
>> options=c01bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,VLAN_HWTSO,LINKSTATE>
>>
>> ether 00:23:7d:23:9d:44
>> inet 1.2.3.144 netmask 0xffffffc0 broadcast 1.2.3.191
>> inet6 fe80::223:7dff:fe23:9d44%bce0 prefixlen 64 scopeid 0x1
>> nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
>> media: Ethernet autoselect (1000baseT<full-duplex>)
>> status: active
>> bce1: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
>> options=c01bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,VLAN_HWTSO,LINKSTATE>
>>
>> ether 00:23:7d:23:9d:42
>> nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
>> media: Ethernet autoselect
>> lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
>> options=3<RXCSUM,TXCSUM>
>> inet6 ::1 prefixlen 128
>> inet6 fe80::1%lo0 prefixlen 64 scopeid 0x9
>> inet 127.0.0.1 netmask 0xff000000
>> nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
>> epair0a: flags=8842<BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu
>> 1500
>> options=8<VLAN_MTU>
>> ether 02:f9:05:00:0a:0a
>> nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
>> media: Ethernet 10Gbase-T (10Gbase-T<full-duplex>)
>> status: active
>> [root at hostname /home/girgen]# jexec bar ifconfig -a
>> lo0: flags=8008<LOOPBACK,MULTICAST> metric 0 mtu 16384
>> options=3<RXCSUM,TXCSUM>
>> nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
>> epair0b: flags=8842<BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu
>> 1500
>> options=8<VLAN_MTU>
>> ether 02:f9:05:00:0b:0b
>> nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
>> media: Ethernet 10Gbase-T (10Gbase-T<full-duplex>)
>> status: active
>> [root at hostname /home/girgen]# jexec bar ifconfig epair0b 10.1.1.2
>> netmask 0xffffff00 up
>> [root at hostname /home/girgen]# jexec bar ping 10.1.1.2
>> PING 10.1.1.2 (10.1.1.2): 56 data bytes
>> ^C
>> --- 10.1.1.2 ping statistics ---
>> 3 packets transmitted, 0 packets received, 100.0% packet loss
>> [root at hostname /home/girgen]# jexec bar route -n get 10.1.1.2
>> route to: 10.1.1.2
>> destination: 10.1.1.2
>> interface: lo0
>> flags:<UP,HOST,DONE,STATIC>
>> recvpipe sendpipe ssthresh rtt,msec mtu weight expire
>> 0 0 0 0 16384 1 0
>> [root at hostname /home/girgen]#
>>
>>
>>
>> Now why would the jail think that lo0 is the way to go to find 10.1.1.2?
>
> That's because 10.1.1.2 is a local address for jail bar and all local
> addresses are reachable via lo0. Keep in mind that this is the vnet's
> lo0 and has nothing to do with the host's lo0. Just "up" your vnet's lo0
> interface and everything will be ok. The lo0 loopback interface is
> prerequisite for networking.
>
> HTH, Nikos
Ah, OK, thanks. I had not grasped that.
But it does not work?
[root at hostname /home/girgen]# jexec bar ifconfig lo0 localhost up
[root at hostname /home/girgen]# jexec bar ifconfig -a
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
options=3<RXCSUM,TXCSUM>
inet6 ::1 prefixlen 128
inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1
inet 127.0.0.1 netmask 0xff000000
nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
epair0b: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu
1500
options=8<VLAN_MTU>
ether 02:f9:05:00:0b:0b
inet6 fe80::f9:5ff:fe00:b0b%epair0b prefixlen 64 scopeid 0x2
inet 10.1.1.2 netmask 0xffffff00 broadcast 10.1.1.255
nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
media: Ethernet 10Gbase-T (10Gbase-T <full-duplex>)
status: active
[root at hostname /home/girgen]# jexec bar ping 10.1.1.2
PING 10.1.1.2 (10.1.1.2): 56 data bytes
^C
--- 10.1.1.2 ping statistics ---
3 packets transmitted, 0 packets received, 100.0% packet loss
[root at hostname /home/girgen]# jexec bar ping localhost
PING localhost (127.0.0.1): 56 data bytes
64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.045 ms
64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.030 ms
^C
--- localhost ping statistics ---
2 packets transmitted, 2 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.030/0.037/0.045/0.007 ms
[root at hostname /home/girgen]#
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