[j-nsp] optimized switchover
Matthias Gelbhardt
matthias at commy.de
Tue Sep 8 05:54:23 EDT 2009
Hi!
I do not understand why, but I do not see packets on the other router.
But there is no icmp either, when I ping the other side. The ES is on
one router, but in routermode. But I have explicitly allowed BFD now.
Strange, I do not understand, why the tcpdump is not working correctly.
Matthias
Nilesh Khambal schrieb:
> Hi Matthias,
>
> I am no expert on J-Seris, but looking at BFD state, I feel that there is an
> issue sending or receiving BFD packets on your Router B. AdminDown state
> here may mean that no packets were ever received from Router A. If you are
> running a Junos Enhanced Services version on these J-Series routers, can you
> check if any specific policy needs to be created to allow these BFD packets
> (UDP/3784)? Also, check if any firewall filters blocking BFD packets. Try to
> run tcpdump on both routers to see if BFD packets are being received or not.
>
>
> Thanks,
> Nilesh.
>
>
> On 9/8/09 1:40 AM, "Matthias Gelbhardt" <matthias at commy.de> wrote:
>
>> Hi!
>>
>> No, actually they are directly connected, so I do not know, why there is
>> a multihop output. Perhaps somehow he thinks to be not directly
>> connected and that is the problem?
>>
>> Both routers are J6350.
>>
>> Regards,
>>
>> Matthias
>>
>> Nilesh Khambal schrieb:
>>> Hi Matthias,
>>>
>>> Are these peers established over a directly connected IPs or is this an
>>> indirect session?
>>>
>>> The session shows multihop on both routers from the show output provided
>>> below.
>>>
>>> What is the router platform on both sides?
>>>
>>> Thanks,
>>> Nilesh
>>>
>>>
>>> On 9/8/09 1:25 AM, "Matthias Gelbhardt" <matthias at commy.de> wrote:
>>>
>>>> Hi!
>>>>
>>>> That is the doc I have used for configuring.
>>>>
>>>> Both routers are Juniper routers over a Laver 2 Link directly connected.
>>>> One router is 9.3R2.8 The other 9.4R2.9.
>>>>
>>>> Regards,
>>>>
>>>> Matthias
>>>>
>>>> Nilesh Khambal schrieb:
>>>>> Hi Matthias,
>>>>>
>>>>> What JUNOS version are you running on this router? Is other end router also
>>>>> a Juniper router? Are both peers directly connected or is this a multihop
>>>>> session?
>>>>>
>>>>> Try this doc link see if it can help.
>>>>>
>>>>>
> http://www.juniper.net/techpubs/software/junos/junos85/swconfig85-routing/i>>>>
> d
>>>>> -13279139.html#id-13279139
>>>>>
>>>>> Thanks,
>>>>> Nilesh.
>>>>>
>>>>>
>>>>>
>>>>> On 9/8/09 12:53 AM, "Matthias Gelbhardt" <matthias at commy.de> wrote:
>>>>>
>>>>>> Has no one an idea? It seems, that I am really stuck here. Do I have to
>>>>>> activate something on the other side (hence the AdminDown status?)
>>>>>>
>>>>>> Regards,
>>>>>>
>>>>>> Matthias
>>>>>>
>>>>>> Matthias Gelbhardt schrieb:
>>>>>>> Hello David,
>>>>>>>
>>>>>>> great tip. Unfortunatly BFD for BGP - though detailed documented - has
>>>>>>> no examples flying around. Perhaps I am missing something here.
>>>>>>>
>>>>>>> I have two routers connected via iBGP. I have tried to make the
>>>>>>> configuration rather simple (only the important parts, BGP session is up
>>>>>>> and running):
>>>>>>>
>>>>>>> This is the same on both sides (change in the IP-addresses of course)
>>>>>>>
>>>>>>> protocols bgp {
>>>>>>> group internal {
>>>>>>> type internal;
>>>>>>> neighbor 91.190.xxx.xxx {
>>>>>>> local-address 91.190.xxx.xxx;
>>>>>>> bfd-liveness-detection {
>>>>>>> minimum-interval 1000;
>>>>>>> multiplier 3;
>>>>>>> }
>>>>>>> }
>>>>>>> }
>>>>>>>
>>>>>>> Router A:
>>>>>>> show bfd session extensive
>>>>>>> Detect Transmit
>>>>>>> Address State Interface Time Interval
>>>>>>> Multiplier
>>>>>>> 91.190.xxx.xxx Init 3.000 1.000 3
>>>>>>> Client BGP, TX interval 1.000, RX interval 1.000
>>>>>>> Session down time 00:00:04
>>>>>>> Local diagnostic CtlExpire, remote diagnostic None
>>>>>>> Remote state Down, version 1
>>>>>>> Min async interval 1.000, min slow interval 1.000
>>>>>>> Adaptive async TX interval 1.000, RX interval 1.000
>>>>>>> Local min TX interval 1.000, minimum RX interval 1.000, multiplier 3
>>>>>>> Remote min TX interval 1.000, min RX interval 1.000, multiplier 3
>>>>>>> Local discriminator 1, remote discriminator 1
>>>>>>> Echo mode disabled/inactive, no-absorb, no-refresh, update-adj
>>>>>>> Multi-hop, min-recv-TTL 0, route table 0, local-address 91.190.xxx.xxx
>>>>>>>
>>>>>>> 1 sessions, 1 clients
>>>>>>> Cumulative transmit rate 1.0 pps, cumulative receive rate 1.0 pps
>>>>>>>
>>>>>>> Router B:
>>>>>>> show bfd session extensive
>>>>>>> Detect Transmit
>>>>>>> Address State Interface Time Interval
>>>>>>> Multiplier
>>>>>>> 91.190.xxx.xxx Down 0.000 1.000 3
>>>>>>> Client BGP, TX interval 1.000, RX interval 1.000
>>>>>>> Local diagnostic None, remote diagnostic None
>>>>>>> Remote state AdminDown, version 1
>>>>>>> Min async interval 1.000, min slow interval 1.000
>>>>>>> Adaptive async TX interval 1.000, RX interval 1.000
>>>>>>> Local min TX interval 1.000, minimum RX interval 1.000, multiplier 3
>>>>>>> Remote min TX interval 0.000, min RX interval 0.000, multiplier 0
>>>>>>> Local discriminator 1, remote discriminator 0
>>>>>>> Echo mode disabled/inactive, no-absorb, no-refresh
>>>>>>> Multi-hop route table 0, local-address 91.190.xxx.xxx
>>>>>>>
>>>>>>> 1 sessions, 1 clients
>>>>>>> Cumulative transmit rate 1.0 pps, cumulative receive rate 0.0 pps
>>>>>>>
>>>>>>> I see the diagnostic on router A but do not understand it. I thought the
>>>>>>> minimum-interval might be too low, so I set it up to a thousand.
>>>>>>>
>>>>>>> Regards,
>>>>>>>
>>>>>>> Matthias
>>>>>>>
>>>>>>>
>>>>>>> David Ball schrieb:
>>>>>>>> There are likely several answers to that, all dependant on your
>>>>>>>> topology and protocol use. But, a good place to start would be BFD
>>>>>>>> (bidirectional forwarding detection). Juniper has decent support for
>>>>>>>> it working with other protocols (OSPF, ISIS, BGP, RIP), notifying them
>>>>>>>> that something may be wrong, allowing them to then make a decision
>>>>>>>> (support may differ from protocol to protocol). That may be a good
>>>>>>>> start point.
>>>>>>>>
>>>>>>>> http://www.juniper.net/techpubs/software/junos/junos95/swconfig-routing/
>>>>>>>> sw
>>>>>>>> co
>>>>>>>> nfig-routing-IX.html#B
>>>>>>>>
>>>>>>>>
>>>>>>>> David B
>>>>>>>>
>>>>>>>>
>>>>>>>> 2009/9/6 Matthias Gelbhardt <matthias at commy.de>:
>>>>>>>>> Hi!
>>>>>>>>>
>>>>>>>>> I wonder what the best practices for optimized switchovers would be?
>>>>>>>>> I mean
>>>>>>>>> fast comprehension of failed BGP connections? A fibre cut or
>>>>>>>>> something like
>>>>>>>>> that, how can I be sure, that my routers are detecting the failed
>>>>>>>>> session as
>>>>>>>>> soon as possible? What would be the best practices fpr that?
>>>>>>>>>
>>>>>>>>> Regards,
>>>>>>>>>
>>>>>>>>> Matthias
>>>>>>>>> _______________________________________________
>>>>>>>>> juniper-nsp mailing list juniper-nsp at puck.nether.net
>>>>>>>>> https://puck.nether.net/mailman/listinfo/juniper-nsp
>>>>>>>>>
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