[j-nsp] BGP Graceful Restart

[Gary Tate]

The helper router keeps track of updates while the restarting router 
brings up rpd and restarts sessions.  Routing tables are then 
synchronized so it does not matter in this case.  Network state is 
retrieved and no packets are lost during this process.

The network is not aware of the change in state of the restarting 
router only the adjacent helper or peering routers.  If the restarting 
router fails to come out of restart (restart timers) then the helper 
routers will act accordingly, as if the router had gone down.

Gary Tate

On Sep 22, 2004, at 3:49 PM, Wayne E. Bouchard wrote:

> If an update is missed and the routing table gets out of sync during
> the switchover process or an access list manages to get bypassed, then
> yes, it matters. The question is how MUCH does it matter?
>
> I'd still rather have that than nothing at all. For me, I can more
> easily deal with a moment or two of oddities than 5 to 10 minutes as
> things resynchronize.
>
> -Wayne
>
> On Wed, Sep 22, 2004 at 02:19:25PM -0700, Harry Reynolds wrote:
>> I believe it is expected that IGP adjacencies and BGP sessions will 
>> bounce
>> as the new RE takes over. We do not replicate protocol state between 
>> the
>> REs. The goal of GR is not to preserve the control plane, I.e., to 
>> keep an
>> adjacency up. The goal is to permit forwarding while the control plane
>> restarts. Put another way, I think it a far better test to generate 
>> some
>> traffic over the BGP/IS-IS session/adjacencies and see what happens to
>> traffic flow during RE removal. If an adjacencies bounces, and no 
>> packets
>> are lost, then does it really matter?
>>
>>
>>
>> HTHs
>>
>>
>>
>>> -----Original Message-----
>>> From: juniper-nsp-bounces at puck.nether.net
>>> [mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of
>>> Khawaja, Kashif
>>> Sent: Wednesday, September 22, 2004 2:11 PM
>>> To: juniper-nsp at puck.nether.net
>>> Subject: [j-nsp] BGP Graceful Restart
>>>
>>> Hi All:
>>>
>>> Trying to test Graceful Restarts for different protocols and
>>> seem to be having a little trouble getting it to work.
>>> I have an M40 and M160 connected to each other and running
>>> isis and bgp.
>>> If I were to pull the active RE on the 160 the isis and bgp
>>> adjacency bounce. I have the following configuration in on
>>> both the routers:
>>> routing-options {
>>>     graceful-restart;
>>>     static {
>>>         route 172.16.0.0/16 next-hop 172.19.253.1;
>>>     }
>>> }
>>>
>>> And also the RE switchover config in for the 160.
>>>
>>> chassis {
>>>     redundancy {
>>>         failover on-loss-of-keepalives;
>>>         graceful-switchover {
>>>             enable;
>>>         }
>>>     }
>>> }
>>>
>>> Am I missing something?
>>>
>>> Thanks.
>>> Kashif.
>>> _______________________________________________
>>> juniper-nsp mailing list juniper-nsp at puck.nether.net
>>> http://puck.nether.net/mailman/listinfo/juniper-nsp
>>>
>>
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>
> ---
> Wayne Bouchard
> web at typo.org
> Network Dude
> http://www.typo.org/~web/
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