FRR 10.2 upgrade - lost static routes and bgp graceful-restart

[SwimGeek]

Description

In the process of upgrading from FRR 10.1.1 to 10.2 I noticed frr.conf had lost all the static routes in the config (v4 and v6). I did a diff on the old and new config files and found a few other missing items.

• static routes missing
• bgp neighbor graceful-restart - removed from IBGP configs
• settings removed from a vlan interface
  - ipv6 nd adv-interval-option
  - ipv6 nd managed-config-flag

Version

FRRouting 10.2 (cpt-ter-rs1) on Linux(6.1.44-atomic).
Debian 12

How to reproduce

I upgraded a router, restarted FRR, then ran vtysh - then write mem - with the idea to update the config file with new FRR version number. Somewhere in this process I ended up without static routes in the newly written config file.

Expected behavior

Keep the configured static routes after an upgrade.

Actual behavior

frr.conf changed, losing static routes

Additional context

No response

Checklist

• I have searched the open issues for this bug.
• I have not included sensitive information in this report.

[ton31337]

Could you show the configs before/after?

[SwimGeek]

Hi

Here is the diff, from backup the day before.

diff -w /root/host-cpt-ter-rs1-frr.conf frr.conf ⏎

1c1
< frr version 10.1.1

frr version 10.2
114,120c114,118
< interface br0.20
< vrrp 1
< vrrp 1 ip 102.216.76.33
< vrrp 1 ipv6 2c0f:ef18:0:2::33
< vrrp 2
< vrrp 2 ip 102.135.240.33
< vrrp 2 ipv6 2c0f:ef18:0:2::1

---

interface vlan328
ipv6 nd other-config-flag
ipv6 nd prefix 2c0f:ef18:8001::/64 off-link no-autoconfig
ipv6 nd ra-interval 10
no ipv6 nd suppress-ra
154,169c152,158
< interface vlan300
< ipv6 nd adv-interval-option
< ipv6 nd managed-config-flag
< ipv6 nd other-config-flag
< ipv6 nd prefix 2c0f:ef18:8000::/64 off-link no-autoconfig
< ipv6 nd ra-interval 10
< no ipv6 nd suppress-ra
< exit
< !
< interface vlan328
< ipv6 nd adv-interval-option
< ipv6 nd managed-config-flag
< ipv6 nd other-config-flag
< ipv6 nd prefix 2c0f:ef18:8001::/64 off-link no-autoconfig
< ipv6 nd ra-interval 10
< no ipv6 nd suppress-ra

---

interface br0.20
vrrp 1
vrrp 1 ip 102.216.76.33
vrrp 1 ipv6 2c0f:ef18:0:2::33
vrrp 2
vrrp 2 ip 102.135.240.33
vrrp 2 ipv6 2c0f:ef18:0:2::1
214d202
< neighbor ATOMIC-IBGP-CORE-v4 graceful-restart
220d207
< neighbor ATOMIC-IBGP-CORE-v6 graceful-restart
225d211
< neighbor ATOMIC-IBGP-EDGE-v4 graceful-restart
230d215
< neighbor ATOMIC-IBGP-EDGE-v6 graceful-restart

[SwimGeek]

I upgraded two other routers, which kept their static routes, but also had the 'neighbor NNN graceful-restart' lines removed.

I looked through the log files, did not find anything useful.

By the time I saved this I already went and pasted back the static routes - had customers complaining.

So 28x 'ip route' and 'ipv6 route' statements not in the diff above. I can't be sure all 28 went missing - but sure about at least 4.

I did the 'write mem' command to create the new config file a few seconds after it started up, so I'm also not sure if that caused the problem, or if it started up without the static routes.

[ton31337]

Please give us not the diff, but real configs to load them and see a real case.

[SwimGeek]

Hi, can't really publish customer routing info on a public forum. Can I share the config just with you?

[ton31337]

Yes, you can send it to me by email or in Slack.

[ton31337]

Thanks. The graceful-restart issue (with peer-groups) is a known regression and it's fixed in stable/10.2, but gonna be released with 10.2.1... Checking yet regarding static routes if this is an issue from the FRR side or not.

[ton31337]

@SwimGeek how about static routes? Can it be somehow reproduced?

[SwimGeek]

Hi, we upgraded a 2nd switch with the same hardware to 10.2, but did not encounter the same issue. Still not sure what caused it. I guess I'll just always do a diff after upgrade going forward to see if I can spot the issue again.