Hi,
I wonder how VyOS selects the IP with which it responds in a traceroute when VRRP is configured.
My gateways have native IPv4 and IPv6 configured (194.156.22.121 and .121 as well as 2001:678:ddc::ff01 and 2001:678:ddc::ff02). VRRP is configured to .1 and ::1 in the same subnet.
For IPv4 it seems to be the physical (aka non-VRRP) address as one can see in this traceroute from a host with the default pointint to the VRRP IP:
# mtr -n -w 8.8.8.8
Start: 2020-10-12T09:44:13+0200
HOST: gw31 Loss% Snt Last Avg Best Wrst StDev
1.|-- 194.156.22.121 0.0% 10 1.1 0.6 0.4 1.1 0.2
2.|-- 185.1.74.31 0.0% 10 2.2 1.3 1.0 2.2 0.4
3.|-- 212.227.112.41 0.0% 10 1.4 2.9 1.1 16.3 4.8
4.|-- 108.170.251.193 0.0% 10 0.8 2.1 0.7 12.8 3.8
5.|-- 216.239.40.59 0.0% 10 0.8 2.2 0.7 14.7 4.4
6.|-- 8.8.8.8 0.0% 10 0.9 0.7 0.6 0.9 0.1
However for IPv6 it responds with the VRRP IP:
# mtr -n -w 2001:4860:4860::8888
Start: 2020-10-12T09:47:13+0200
HOST: gw31 Loss% Snt Last Avg Best Wrst StDev
1.|-- 2001:678:ddc::1 0.0% 10 0.6 1.2 0.5 4.5 1.5
2.|-- 2001:7f8:a5::4:7147:1 0.0% 10 0.9 1.1 0.7 1.8 0.3
3.|-- 2001:4860:1:1::6bc 0.0% 10 7.6 2.4 0.7 9.1 3.2
4.|-- 2001:4860:0:11e1::1 20.0% 10 4.6 2.4 1.8 4.6 0.9
5.|-- 2001:4860:0:1::4935 20.0% 10 13.9 13.8 13.6 13.9 0.1
6.|-- 2001:4860:4860::8888 0.0% 10 1.0 1.0 0.9 1.1 0.1
I wonder if this behaviour is by design or by chance? Is there any way to configure with which IP my router will respond in traceroutes? If not would it be wise to open a topic as feature request or create a ticket in phabricator?