[Xorp-users] subnet routes & xorp

[Pavlin Radoslavov]

> >> Does xorp do the equivalent of 'ifconfig down ethx; ifconfig up ethx' when
> >> you add and/or delete an interface & vif?
> >>
> >> A subnet route is disappearing from and interface that I removed
> >> from one xorp instance and added to another, and if it's bouncing the
> >> interface, that could explain why...

On second reading I realized this is what might be happening.
If an interface is removed, then a protocol that uses that interface
might attempt to withdraw all routes pointing toward that interface.
I think this is the case for Static for example, and I guess this
might be the case for OSPF as well.

You should enable XRLTRACE to see what XRLs are exchanged when the
interface is deleted inside the XORP configuration. This will tell
you whether the route deletion is originated by XORP (and by which
module).

In addition, "ip monitor" will tell you what events actually happen
inside the kernel.

If the above is not sufficient to find the problem, XLOG_INFO() at
the bottom of the FEA inside the Linux plugins will tell you what
exactly happens between the FEA and the kernel.

Regards,
Pavlin


> > The "down/up" operations should happen only in certain situations
> > when are really needed. E.g., setting the MTU or the MAC address are
> > two examples that come to mind: the interface must be in DOWN state
> > otherwise the setting will fail.
> > 
> > The Linux "ip monitor" in a separate xterm will tell you whether the
> > "down/up" operations actually happen in your case.
> 
> It looks like Xorp is removing it, but I could be wrong.
> 
> I'm not changing MAC or MTU.
> 
> My comments inline with # prefix
> 
> # Start of my script's commands
> Deleted 10:     from all to 10.0.0.2 iif rddVR44 lookup local
> Deleted 10:     from all to 10.4.0.7 iif rddVR44 lookup local
> Deleted 10:     from all to 10.4.0.7 iif rddVR1 lookup local
> Deleted 20:     from all iif rddVR44 lookup 10001
> Deleted 30:     from 10.4.0.7 lookup 10001
> 10:     from all to 10.4.0.7 iif rddVR44 lookup local
> 10:     from all to 10.0.0.1 iif rddVR44 lookup local
> 10:     from all to 10.2.0.1 iif rddVR44 lookup local
> 10:     from all to 10.3.0.1 iif rddVR44 lookup local
> 10:     from all to 10.4.0.7 iif rddVR0 lookup local
> 10:     from all to 10.4.0.7 iif rddVR3 lookup local
> 10:     from all to 10.4.0.7 iif br2 lookup local
> 20:     from all iif rddVR44 lookup 10002
> 30:     from 10.4.0.7 lookup 10002
> 10.4.0.0/24 via 10.4.0.7 dev rddVR44  table 10002
> 
> # my script should be done at this point and now calling into
> # xorpsh  Looks like the routes go away here, maybe because
> # Xorp is removing the IP address when I delete the interface
> # through xorpsh?
> 
> Deleted 71: rddVR44    inet 10.4.0.7/24 brd 10.4.0.255 scope global rddVR44
> Deleted 10.4.0.0/24 dev rddVR44  proto kernel  scope link  src 10.4.0.7
> Deleted broadcast 10.4.0.255 dev rddVR44  table local  proto kernel  scope link  src 10.4.0.7
> Deleted broadcast 10.4.0.0 dev rddVR44  table local  proto kernel  scope link  src 10.4.0.7
> Deleted local 10.4.0.7 dev rddVR44  table local  proto kernel  scope host  src 10.4.0.7
> 
> # Specifically, here's the ones in my special routing table
> Deleted 10.1.0.0/24 via 10.0.0.2 dev rddVR0  table 10002  proto xorp  metric 3 notify
> Deleted 10.4.0.0/24 via 10.0.0.2 dev rddVR0  table 10002  proto xorp  metric 2 notify
> 
> # Now it seems Xorp is re-adding them, but it doesn't know how to deal with
> # my special table, so in the end, my routes are not quite right...
> 
> 71: rddVR44    inet 10.4.0.7/24 brd 10.4.0.255 scope global rddVR44
> local 10.4.0.7 dev rddVR44  table local  proto kernel  scope host  src 10.4.0.7
> broadcast 10.4.0.255 dev rddVR44  table local  proto kernel  scope link  src 10.4.0.7
> 10.4.0.0/24 dev rddVR44  proto kernel  scope link  src 10.4.0.7
> broadcast 10.4.0.0 dev rddVR44  table local  proto kernel  scope link  src 10.4.0.7
> 
> 
> Thanks,
> Ben
> 
> 
> -- 
> Ben Greear <greearb at candelatech.com>
> Candela Technologies Inc  http://www.candelatech.com
> 
> _______________________________________________
> Xorp-users mailing list
> Xorp-users at xorp.org
> http://mailman.ICSI.Berkeley.EDU/mailman/listinfo/xorp-users