tests/bgp-frr-srv6: init

[felbinger]

I initially set up this topology in VyOS on a Proxmox Server. While in the VyOS environment everything works, replacing PE3 with a similar NixOS setup breaks ipv4 forwarding for customer B. Beside ip rule prio 0 I have not found any differences yet. In the test the forwarding is completely broken

After forwarding has been fixed (test cases should be ok) I'd like to try migrating PE2 to GoBGP. According to https://www.segment-routing.net/open-software GoBGP already supports SRv6. Afterwards I'm going to rename the test to bgp-srv6.

Additional Resources:

• https://bun.pages.forge.hefr.ch/docs/netsimulation/FRR/srv6/
• https://github.com/rodonile/clab-srv6-frr
• https://www.linkedin.com/pulse/poc-frrouting-srv6-l3vpn-ipv4-ipv6and-wireguard-vpn-gonzalez-diaz
• https://oneuptime.com/blog/post/2026-03-20-configure-srv6-linux-iproute2/view
• https://srv6.md/implementations/linux-kernel/
• https://lwn.net/Articles/823946/

[felbinger]

It should look like this:

# pe3 (ping from ce4)
18:25:30.743461 ens20 In  IP6 3fff:bbbb:2::100 > 3fff:bbbb:1::100: ICMP6, echo request, id 9491, seq 1, length 64
18:25:30.743519 ens19 Out IP6 PE3 > 2001:db8:1:aaa:66::: RT6 (len=2, type=4, segleft=0, last-entry=0, tag=0, [0]2001:db8:1:aaa:66::) IP6 3fff:bbbb:2::100 > 3fff:bbbb:1::100: ICMP6, echo request, id 9491, seq 1, length 64
18:25:30.744676 ens19 In  IP6 2001:db8:1:ffff::1 > 2001:db8:3:aaa:66::: RT6 (len=2, type=4, segleft=0, last-entry=0, tag=0, [0]2001:db8:3:aaa:66::) IP6 3fff:bbbb:1::100 > 3fff:bbbb:2::100: ICMP6, echo reply, id 9491, seq 1, length 64
18:25:30.744700 ens20 Out IP6 3fff:bbbb:1::100 > 3fff:bbbb:2::100: ICMP6, echo reply, id 9491, seq 1, length 64

But it looks like this:

# pe1 (ping from ce1)
18:32:22.245367 eth2  In  IP6 3fff:aaaa:1::100 > 3fff:aaaa:2::100: ICMP6, echo request, id 7, seq 2, length 64
18:32:22.245471 eth4  Out IP6 pe1 > 2001:db8:2:aaa:65::: RT6 (len=2, type=4, segleft=0, last-entry=0, tag=0, [0]2001:db8:2:aaa:65::) IP6 3fff:aaaa:1::100 > 3fff:aaaa:2::100: ICMP6, echo request, id 7, seq 2, length 64

# pe1 (ping from ce3)
18:34:52.804597 eth3  In  IP6 3fff:bbbb:1::100 > 3fff:bbbb:2::100: ICMP6, echo request, id 2, seq 2, length 64
18:34:52.804710 eth1  Out IP6 pe1 > 2001:db8:3:aaa:66::: RT6 (len=2, type=4, segleft=0, last-entry=0, tag=0, [0]2001:db8:3:aaa:66::) IP6 3fff:bbbb:1::100 > 3fff:bbbb:2::100: ICMP6, echo request, id 2, seq 2, length 64

# pe2 (ping from ce1)
18:32:21.202348 eth3  In  IP6 2001:db8:1:ffff::1 > 2001:db8:2:aaa:65::: RT6 (len=2, type=4, segleft=0, last-entry=0, tag=0, [0]2001:db8:2:aaa:65::) IP6 3fff:aaaa:1::100 > 3fff:aaaa:2::100: ICMP6, echo request, id 7, seq 1, length 64

# pe3 (ping from ce3)
18:34:51.167509 eth1  In  IP6 2001:db8:1:ffff::1 > 2001:db8:3:aaa:66::: RT6 (len=2, type=4, segleft=0, last-entry=0, tag=0, [0]2001:db8:3:aaa:66::) IP6 3fff:bbbb:1::100 > 3fff:bbbb:2::100: ICMP6, echo request, id 2, seq 1, length 64