GRE in a fib via rc.conf

From: Mark Saad <nonesuch_at_longcount.org>
Date: Tue, 08 Nov 2022 00:26:32 UTC
All
  I am looking for some help on if my setup makes sense.
I have a vm with two interfaces. One for access to the host , we'll call
this mgmt . One for routing traffic, we'll call this routing . I want to
put the routing interface into a fib and to run a gre tunnel over it.
Sounds simple enough.  The problem I am seeing is that it looks like the
tunneled traffic is leaked into the default fib and I don't see why. I am
not sure if this is config nit or if this is an issue. Should the gre10
interface be in fib 1 ?  See below.

### RC CONF ###
ifconfig_vmx0="inet 10.23.121.253/24 description mgmt"
ifconfig_vmx1="inet 100.65.101.14/28 mtu 9000 description routing fib 1"
defaultrouter="10.23.121.1"
static_routes="ewr10gresrc"
route_ewr10gresrc=" 192.168.255.14 100.65.101.1 -fib 1"
cloned_interfaces="gre10"
ifconfig_gre10=" inet 100.67.103.2 100.67.103.1 netmask 255.255.255.252
tunnel 100.65.101.14 192.168.255.14 tunnelfib 1"
###############

### DEFAULT FIB ###
~ # netstat -nr4Wl
Routing tables

Internet:
Destination Gateway Flags Nhop# Mtu Netif Expire
default 10.23.121.1 UGS 6 1500 vmx0
10.23.121.0/24 link#1 U 2 1500 vmx0
10.23.121.253 link#1 UHS 3 16384 lo0
100.67.103.1 link#4 UH 4 1476 gre10
100.67.103.2 link#4 UHS 5 16384 lo0
127.0.0.1 link#3 UH 1 16384 lo0

### FIB 1 ###

# setfib 1 netstat -nr4Wl
Routing tables (fib: 1)

Internet:
Destination Gateway Flags Nhop# Mtu Netif Expire
100.65.101.0/28 link#2 U 1 9000 vmx1
100.65.101.14 link#2 UHS 2 16384 lo0
127.0.0.1 link#3 UHS 3 16384 lo0
192.168.255.14 100.65.101.1 UGHS 4 9000 vmx1

##### PING EXAMPLES #####

# setfib 1 ping -c 1 -t 2 100.67.103.1
PING 100.67.103.1 (100.67.103.1): 56 data bytes
ping: sendto: No route to host

--- 100.67.103.1 ping statistics ---
1 packets transmitted, 0 packets received, 100.0% packet loss
# setfib 0 ping -c 1 -t 2 100.67.103.1
PING 100.67.103.1 (100.67.103.1): 56 data bytes
64 bytes from 100.67.103.1: icmp_seq=0 ttl=255 time=1.528 ms

--- 100.67.103.1 ping statistics ---
1 packets transmitted, 1 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 1.528/1.528/1.528/0.000 ms

#### TCPDUMP ####
ICMP packets are in fact sourced from the gre10 interface.
The GRE packets are also only going out the routing interface.

See the following pastebin for details.

https://pastebin.com/n3mGXGHA




-- 
mark saad | nonesuch@longcount.org