ipv6 link local address @ bridge

RouterOS General
1

Hi,

Is it new behavior in v6.38 that the bridge interfaces only get a IPv6 link local address if auto-mac=yes? This got me wondering why my router advertisement stopped working after the upgrade from v6.37.3 for a moment. Can anybody confirm my assumption?

Greetings,
Wil

2

Quick test with CHR 6.38.1 looks ok:

[sob@test] /interface bridge> print 
Flags: X - disabled, R - running 
 0  R name="bridge1" mtu=auto actual-mtu=1500 l2mtu=65535 arp=enabled arp-timeout=auto 
      mac-address=00:0C:29:48:04:BA protocol-mode=rstp priority=0x8000 auto-mac=yes 
      admin-mac=00:00:00:00:00:00 max-message-age=20s forward-delay=15s transmit-hold-count=6 
      ageing-time=5m 

 1  R name="bridge2" mtu=auto actual-mtu=1500 l2mtu=65535 arp=enabled arp-timeout=auto 
      mac-address=FE:12:34:56:78:90 protocol-mode=rstp priority=0x8000 auto-mac=no 
      admin-mac=FE:12:34:56:78:90 max-message-age=20s forward-delay=15s transmit-hold-count=6 
      ageing-time=5m 
[sob@test] /interface bridge> /ipv6 address print 
Flags: X - disabled, I - invalid, D - dynamic, G - global, L - link-local 
 #    ADDRESS                                     FROM-POOL INTERFACE                 ADVERTISE
 ...
 3 DL fe80::20c:29ff:fe48:4ba/64                            bridge1                   no
 4 DL fe80::fc12:34ff:fe56:7890/64                          bridge2                   no
3

Hi,

I tried to reproduce the issue on another router. But I could not reproduce the missing link local address on the bridge interface regardless of auto-mac yes or no. Maybe it was just a glitch with my configuration that has been carried over from ROS v5 times. Anyway thanks for taking a look!

Bye,
Wil

4

This is probably a long time problem. I’m seeing problem with missing link local address on the bridge from time of the ROS5.2x version. Sometimes, after ROS starts there are missing link local address on the one or more bridge interfaces. Very similar problem with VRRP interfaces - link local address is showed but do not works.

One possible solution is script which in loop disable/enable bridge interface until link local address is assigned (on VRRP is problem solved after transit among master/slave/master states).

Related to the IPv6 link local addreess: I’m missing possibility to add manual IPv6 link local address. For example on the PtP link where one end to have fe80::1 and second fe80::2…