[FROG] Is there an IPv6 forwarding bug in FRR running in namespace?

[Peter Olsson]

Or am I doing it wrong? (But it works in quagga.)

Debian 10.5.
FRR tried both 6.0.2 and 7.3.1.
Installed package is frr-snmp.

This is what i do:

/etc/sysctl.d/local.conf:
net.ipv4.ip_forward=1
net.ipv6.conf.all.forwarding=1

mkdir -p /run/frr/$NS
chown frr:frr /run/frr/$NS
/sbin/ip netns add $NS
/sbin/ip netns exec $NS /sbin/ip link set dev lo up

Create two interfaces, one of which is a veth peer to a veth interface in the default namespace.
Both interfaces have IPv4 and IPv6 addresses.

/sbin/ip netns exec $NS /usr/lib/frr/zebra -d -A 127.0.0.1 -s 90000000 -N $NS
/sbin/ip netns exec $NS /usr/lib/frr/bgpd -d -A 127.0.0.1 -N $NS
/sbin/ip netns exec $NS /usr/lib/frr/ospfd -d -A 127.0.0.1 -N $NS
/sbin/ip netns exec $NS /usr/lib/frr/ospf6d -d -A 127.0.0.1 -N $NS
/sbin/ip netns exec $NS /usr/lib/frr/staticd -d -A 127.0.0.1 -N $NS

cat /proc/sys/net/ipv6/conf/*/forwarding show all ones.
(However, the namespace interfaces aren't displayed in
/proc/sys/net/ipv6/conf, just the default namespace interfaces.
But the same goes for IPv4, and I have no problems with IPv4.)

In /etc/frr/$NS/zebra.conf I have this configuration:
"
frr version 7.3.1
frr defaults traditional
hostname xxx
password xxx
enable password xxx
log syslog informational
log facility local6
!
interface xxx
 ip address xxx
 ipv6 address xxx
!
interface veth-xxx-C
 ip address xxx
 ipv6 address xxx
!
line vty
 exec-timeout 60 0
"

Every time I reboot this server, ipv6 forwarding is turned off in the namespace zebra.
ipv6 forwarding works fine in the default namespace, and ipv4 forwarding works fine
both in $NS and the default namespace.


# ip netns exec ipvpn-gotanet telnet localhost 2601
Hello, this is FRRouting (version 7.3.1).
# sh run
...
no ipv6 forwarding
...
# sh ip for
IP forwarding is on
# sh ipv for
ipv6 forwarding is off

sh start doesn't display the "no ipv6 forwarding" line.


I also noticed that two other FRR servers, running Debian 10.3, have the same problem,
showing "no ipv6 forwarding" in the running zebra configuration. Those two servers
don't use IPv6 in namespaces, so I haven't noticed this problem in them before now.

This has never been a problem in quagga.

Thanks!

Peter Olsson