The ISP's dampening will cut you off?

Sent from my iPhone

On Oct 12, 2012, at 10:01 AM, Marko Milivojevic <[email protected]> wrote:

> Well, well... What if it flaps back and forth? :-)
> 
> --
> Marko Milivojevic - CCIE #18427 (SP R&S)
> Senior CCIE Instructor - IPexpert
> 
> On Fri, Oct 12, 2012 at 12:06 AM, vin.ccie29412 <[email protected]> wrote:
>> peering to an hsrp vip will work  ,  fast hellos can be used to minimise
>> the swap delay , in all circumstances bgp will flap .
>> 
>> to have device redundancy to a single upstream pe would sound over spec ,
>> but to a multi node internal external peer would be ideal . A Flap is much
>> better than total loss of service .
>> 
>> Regards
>> 
>> Vin
>> 
>> 
>> 
>> 
>> On Fri, Oct 12, 2012 at 5:47 AM, Marko Milivojevic 
>> <[email protected]>wrote:
>> 
>>> To be honest, I'm as amused as you are with this :-). I'm in a
>>> bootcamp for the next three weeks, but I'll for sure give it a
>>> thorough test when I'm done :-).
>>> 
>>> I'm guessing it can be made to work, as long as HSRP-side is
>>> "passive", i.e. not the one initiating connection. Of course, without
>>> a state exchange between HSRP peers, when there is HSRP failover, BGP
>>> will flap. This is probably why it's not recommended.
>>> 
>>> --
>>> Marko Milivojevic - CCIE #18427 (SP R&S)
>>> Senior CCIE Instructor - IPexpert
>>> 
>>> On Thu, Oct 11, 2012 at 5:16 PM, Nick Bonifacio <[email protected]>
>>> wrote:
>>>> There has to be instability issues, right?  Flapping, arps and macs
>>> getting hosed perhaps?
>>>> 
>>>> *Paging Dr. Marko*
>>>> 
>>>> 
>>>> ________________________________
>>>> From: Tony Singh <[email protected]>
>>>> To: Nick Bonifacio <[email protected]>
>>>> Cc: Bob McCouch <[email protected]>; "[email protected]" <
>>> [email protected]>
>>>> Sent: Thursday, October 11, 2012 6:13 PM
>>>> Subject: Re: [OSL | CCIE_RS] Hello team can we make bgp neighbor ship
>>> HSRP virtual IP ?
>>>> 
>>>> 
>>>> Good work Nick
>>>> 
>>>> I'm sure Cisco know this works..? Why do they not recommend it then ...
>>>> 
>>>> 
>>>> --
>>>> BR
>>>> 
>>>> Tony
>>>> Sent from my iPhone on 3
>>>> 
>>>> On 11 Oct 2012, at 23:06, Nick Bonifacio <[email protected]> wrote:
>>>> 
>>>> 
>>>> 
>>>>> 
>>>>> R5(config-router)#do sh ip b
>>>>> *Oct 11 22:09:20.495: %BGP-5-ADJCHANGE: neighbor 10.0.46.1 Down User
>>> reset
>>>>> *Oct 11 22:09:20.907: %BGP-5-ADJCHANGE: neighbor 10.0.46.1 Up gp
>>>>> BGP table version is 16, local router ID is 10.0.46.55
>>>>> Status codes: s suppressed, d damped, h history, * valid, > best, i -
>>> internal,
>>>>>             r RIB-failure, S Stale
>>>>> Origin codes: i - IGP, e - EGP, ? - incomplete
>>>>> 
>>>>> 
>>>>>  Network          Next Hop            Metric LocPrf Weight Path
>>>>> *>i192.46.1.0       10.0.46.1             1234    100  10000 i
>>>>> *>i192.46.2.0       10.0.46.1             1234    100  10000 i
>>>>> *>i192.46.3.0       10.0.46.1             1234    100  10000 i
>>>>> *>i192.46.4.0       10.0.46.1             1234    100  10000 i
>>>>> *>i192.46.5.0       10.0.46.1             1234    100  10000 i
>>>>> *>i192.46.6.0       10.0.46.1             1234    100  10000 i
>>>>> *>i192.46.7.0       10.0.46.1             1234    100  10000 i
>>>>> *>i192.46.8.0       10.0.46.1             1234    100  10000 i
>>>>> *>i192.46.9.0       10.0.46.1             1234    100  10000 i
>>>>> *>i192.46.10.0      10.0.46.1             1234    100  10000 i
>>>>> *>i192.46.11.0      10.0.46.1             1234    100  10000 i
>>>>> *>i192.46.12.0      10.0.46.1             1234    100  10000 i
>>>>> *>i192.46.13.0      10.0.46.1             1234    100  10000 i
>>>>> *>i192.46.14.0      10.0.46.1             1234    100  10000 i
>>>>> *>i192.46.15.0      10.0.46.1             1234    100  10000 i
>>>>> R5(config-router)#
>>>>> 
>>>>> 
>>>>> i need a fast way to copy and paste prefixes in  :)
>>>>> 
>>>>> 
>>>>> I did manipulate weight, MED...
>>>>> 
>>>>> ________________________________
>>>>> From: Tony Singh <[email protected]>
>>>>> To: Nick Bonifacio <[email protected]>
>>>>> Cc: Bob McCouch <[email protected]>; "[email protected]" <
>>> [email protected]>
>>>>> Sent: Thursday, October 11, 2012 5:54 PM
>>>>> Subject: Re: [OSL | CCIE_RS] Hello team can we make bgp neighbor ship
>>> HSRP virtual IP ?
>>>>> 
>>>>> Take it further see how many prefixes it can handle, check metrics work
>>> weight local pref med...
>>>>> 
>>>>> --
>>>>> BR
>>>>> 
>>>>> Tony
>>>>> 
>>>>> Sent from my iPad
>>>>> 
>>>>> On 11 Oct 2012, at 22:34, Nick Bonifacio <[email protected]> wrote:
>>>>> 
>>>>>> I can't believe it, working on real hardware as well:
>>>>>> 
>>>>>> interface FastEthernet0/0
>>>>>> ip address 10.0.46.6 255.255.255.0
>>>>>> duplex auto
>>>>>> speed auto
>>>>>> standby 0 ip 10.0.46.1
>>>>>> 
>>>>>> 
>>>>>> router bgp 456
>>>>>> no synchronization
>>>>>> bgp log-neighbor-changes
>>>>>> neighbor 10.0.46.55 remote-as 456
>>>>>> no auto-summary
>>>>>> 
>>>>>> 
>>>>>> ------------------------------------------------------------------
>>>>>> 
>>>>>> 
>>>>>> interface FastEthernet0/0
>>>>>> ip address 10.0.46.55 255.255.255.0
>>>>>> duplex
>>>> auto
>>>>>> speed auto
>>>>>> 
>>>>>> 
>>>>>> router bgp 456
>>>>>> no synchronization
>>>>>> bgp log-neighbor-changes
>>>>>> neighbor 10.0.46.1 remote-as 456
>>>>>> no auto-summary
>>>>>> 
>>>>>> 
>>>>>> R5(config-router)#do sh ip bgp sum
>>>>>> BGP router identifier 10.0.46.55, local AS number 456
>>>>>> BGP table version is 1, main routing table version 1
>>>>>> 
>>>>>> Neighbor        V          AS MsgRcvd MsgSent   TblVer  InQ OutQ
>>> Up/Down  State/PfxRcd
>>>>>> 10.0.46.1       4          456       5             5       1         0
>>>             0 00:03:18        0
>>>>>> 
>>>>>> 
>>>>>> R5(config-router)#do sh tcp brief
>>>>>> TCB       Local Address
>>>>                 Foreign Address             (state)
>>>>>> 66A1041C       10.0.46.55.39341            10.0.46.1.179
>>>  ESTAB
>>>>>> 
>>>>>> 
>>>>>> System image file is "flash:c1841-adventerprisek9-mz.124-24.T7.bin"
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> ________________________________
>>>>>> From: Nick Bonifacio <[email protected]>
>>>>>> To: Bob McCouch <[email protected]>
>>>>>> Cc: "[email protected]" <[email protected]>
>>>>>> Sent: Thursday, October 11, 2012 8:51 AM
>>>>>> Subject: Re: [OSL | CCIE_RS] Hello team can we make bgp neighbor ship
>>> HSRP virtual IP ?
>>>>>> 
>>>>>> Just what I need, another OCD day.  Oh well, I'll be home in about 8
>>> hours and will have access to real hardware.  I will let everyone know what
>>> happens.
>>>>>> 
>>>>>> Nick
>>>>>> 
>>>>>> Sent from my iPhone
>>>>>> 
>>>>>> On Oct 11, 2012, at 8:43 AM, Bob McCouch <[email protected]> wrote:
>>>>>> 
>>>>>>> Interesting. I was also pretty sure that didn't work. At best it would
>>>>>>> only do a passive open (respond to a TCP syn) no originate the
>>>>>>> session.
>>>>>>> 
>>>>>>> Bob
>>>>>>> --
>>>>>>> Sent from my iPhone, please excuse any typos.
>>>>>>> 
>>>>>>> On Oct 11, 2012, at 8:25 AM,
>>>> Nick Bonifacio <[email protected]> wrote:
>>>>>>> 
>>>>>>>> //Disclaimer:  I am using GNS3 for this example.
>>>>>>>> 
>>>>>>>> This is the way I understand it, anyone else feel free to chime in:
>>>>>>>> 
>>>>>>>> Think update source.
>>>>>>>> 
>>>>>>>> router bgp 4
>>>>>>>> neighbor 10.0.4.5 remote-as 5
>>>>>>>> neighbor 10.0.4.5 update-source FastEthernet0/0
>>>>>>>> 
>>>>>>>> 
>>>>>>>> interface FastEthernet0/0
>>>>>>>> ip address 10.0.4.4 255.255.255.0
>>>>>>>> duplex auto
>>>>>>>> speed auto
>>>>>>>> standby 0 ip 10.0.4.254
>>>>>>>> 
>>>>>>>> how can I create a neighborship by sourcing the standby 0 IP?  I
>>> can't.
>>>>>>>> 
>>>>>>>> Let's look at router 5 on the other side
>>>>>>>> 
>>>>>>>> interface
>>>> FastEthernet0/0
>>>>>>>> ip address 10.0.4.5 255.255.255.0
>>>>>>>> duplex auto
>>>>>>>> speed auto
>>>>>>>> 
>>>>>>>> router bgp 5
>>>>>>>> no synchronization
>>>>>>>> bgp log-neighbor-changes
>>>>>>>> neighbor 10.0.1.1 remote-as 1
>>>>>>>> neighbor 10.0.4.254 remote-as 4
>>>>>>>> no auto-summary
>>>>>>>> 
>>>>>>>> 
>>>>>>>> Let's debug BGP on R4
>>>>>>>> 
>>>>>>>> R4(config-router)#no
>>>>>>>> *Mar  1 00:31:36.267: BGP: 10.0.4.5 passive open to 10.0.4.254
>>>>>>>> *Mar  1 00:31:36.271: BGP: 10.0.4.5 passive open failed - 10.0.4.254
>>> is not update-source FastEthernet0/0's address (10.0.4.4)
>>>>>>>> *Mar  1 00:31:36.271: BGP: 10.0.4.5 remote connection attempt
>>> failed, local address 10.0.4.254
>>>>>>>> R4(config-router)#no
>>>>>>>> *Mar  1 00:31:38.255: BGP: 10.0.4.5 open active, local address
>>>> 10.0.4.4
>>>>>>>> *Mar  1 00:31:38.311: BGP: 10.0.4.5 open failed: Connection refused
>>> by remote host, open active delayed 26388ms (35000ms max, 28% jitter)
>>>>>>>> R4(config-router)#no
>>>>>>>> 
>>>>>>>> ok it is complaining about 10.0.4.254 not being fa0/0's address.
>>> Fine, I will remove update source fa0/0
>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>>>>>> router bgp 4
>>>>>>>> no synchronization
>>>>>>>> bgp log-neighbor-changes
>>>>>>>> neighbor 10.0.4.2 remote-as 2
>>>>>>>> neighbor 10.0.4.3 remote-as 3
>>>>>>>> neighbor 10.0.4.5 remote-as 5
>>>>>>>> neighbor 10.0.4.5 update-source FastEthernet0/0
>>>>>>>> maximum-paths 3
>>>>>>>> no auto-summary
>>>>>>>> 
>>>>>>>> no neighbor 10.0.4.5 update-source FastEthernet0/0
>>>>>>>> 
>>>>>>>> BGP: 10.0.4.5 rcvd OPEN w/ remote AS 5
>>>>>>>> *Mar  1
>>>> 00:33:09.427: BGP: 10.0.4.5 went from OpenSent to OpenConfirm
>>>>>>>> *Mar  1 00:33:09.427: BGP: 10.0.4.5 send message type 1, length
>>> (incl. header) 45
>>>>>>>> *Mar  1 00:33:09.475: BGP: 10.0.4.5 went from OpenConfirm to
>>> Established
>>>>>>>> *Mar  1 00:33:09.475: %BGP-5-ADJCHANGE: neighbor 10.0.4.5 Up
>>>>>>>> 
>>>>>>>> uh oh, it is working!  Interesting.. I am in GNS3 but will lab it up
>>> at home on real hardware once I get there.  This is not the behavior I
>>> expected.
>>>>>>>> 
>>>>>>>> R5#sh ip bgp sum
>>>>>>>> [...]
>>>>>>>> Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down
>>> State/PfxRcd
>>>>>>>> 10.0.1.1        4     1      40      40        2    0    0 00:36:01
>>>> 1
>>>>>>>> 10.0.4.254      4     4      16      22        2    0    0 00:02:47
>>>       1
>>>>>>>> 
>>>>>>>> 
>>>>>>>> I also tested it with iBGP and the same behavior occured.  I also
>>> failed over the HSRP address and made another node active as 10.0.4.254 and
>>> the adjacency did come back up on that router!
>>>>>>>> 
>>>>>>>> I will try this out on real hardware once I get home and then report
>>> back.  We had tried this in production 2 months ago using ASR1000s and
>>> could not get it working.
>>>>>>>> 
>>>>>>>> Nick
>>>>>>>> 
>>>>>>>> 
>>>>>>>> ________________________________
>>>>>>>> From: Samir Idris <[email protected]>
>>>>>>>> To: Nick Bonifacio <[email protected]>
>>>>>>>> Cc: Taqdir Singh <[email protected]>; "
>>> [email protected]" <[email protected]>
>>>>>>>> Sent: Thursday, October 11, 2012 7:50 AM
>>>>>>>> Subject: Re: [OSL | CCIE_RS] Hello team can we make bgp neighbor
>>> ship HSRP virtual IP ?
>>>>>>>> 
>>>>>>>> 
>>>>>>>> Nick,
>>>>>>>> 
>>>>>>>> Why cant we source from a virtual IP?  Can you shed some light on
>>> the logic?
>>>>>>>> 
>>>>>>>> Regards,
>>>>>>>> Samir.
>>>>>>>> 
>>>>>>>> On Thursday, October 11, 2012, Nick
>>>> Bonifacio <[email protected]> wrote:
>>>>>>>>> Hi Taqdir,
>>>>>>>>> 
>>>>>>>>> You have to source from a physical interface and cannot source from
>>> a vIP.  Here is a link to "best practice" using HSRP and multihomed BGP
>>> environments:
>>> http://www.cisco.com/en/US/tech/tk365/technologies_configuration_example09186a0080093f2c.shtml
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> Thanks!
>>>>>>>>> Nick
>>>>>>>>> 
>>>>>>>>> ________________________________
>>>>>>>>> From: Taqdir Singh <[email protected]>
>>>>>>>>> To: [email protected]
>>>>>>>>> Sent: Thursday, October 11, 2012 3:16 AM
>>>>>>>>> Subject: [OSL | CCIE_RS] Hello team can we make bgp neighbor ship
>>> HSRP virtual IP ?
>>>>>>>>> 
>>>>>>>>> Hello team can we make bgp neighborship with HSRP virtual IP ?
>>>>>>>>> _______________________________________________
>>>>>>>>> For more information regarding industry leading CCIE Lab training,
>>> please visit http://www.ipexpert.com/
>>>>>>>>> 
>>>>>>>>> Are you a CCNP or CCIE and looking for a job? Check out
>>> http://www.platinumplacement.com/
>>>>>>>>> 
>>>>>>>>> http://onlinestudylist.com/mailman/listinfo/ccie_rs
>>>>>>>>> _______________________________________________
>>>>>>>>> For more information regarding industry leading CCIE Lab training,
>>> please visit http://www.ipexpert.com/
>>>>>>>>> 
>>>>>>>>> Are you a CCNP or CCIE and looking for a job? Check out
>>> http://www.platinumplacement.com/
>>>>>>>>> 
>>>>>>>>> http://onlinestudylist.com/mailman/listinfo/ccie_rs
>>>>>>>> 
>>>>>>>> --
>>>>>>>> Samir Idris
>>>>>>>> _______________________________________________
>>>>>>>> For more information regarding industry leading CCIE Lab training,
>>> please visit www.ipexpert.com
>>>>>>>> 
>>>>>>>> Are
>>>> you a CCNP or CCIE and looking for a job? Check out
>>> www.PlatinumPlacement.com
>>>>>>>> 
>>>>>>>> http://onlinestudylist.com/mailman/listinfo/ccie_rs
>>>>>> _______________________________________________
>>>>>> For more information regarding industry leading CCIE Lab training,
>>> please visit www.ipexpert.com
>>>>>> 
>>>>>> Are you a CCNP or CCIE and looking for a job? Check out
>>> www.PlatinumPlacement.com
>>>>>> 
>>>>>> http://onlinestudylist.com/mailman/listinfo/ccie_rs
>>>>>> _______________________________________________
>>>>>> For more information regarding industry leading CCIE Lab training,
>>> please visit www.ipexpert.com
>>>>>> 
>>>>>> Are you a CCNP or CCIE and looking for a job? Check out
>>> www.PlatinumPlacement.com
>>>>>> 
>>>>>> http://onlinestudylist.com/mailman/listinfo/ccie_rs
>>>> _______________________________________________
>>>> For more information regarding industry leading CCIE Lab training,
>>> please visit www.ipexpert.com
>>>> 
>>>> Are you a CCNP or CCIE and looking for a job? Check out
>>> www.PlatinumPlacement.com
>>>> 
>>>> http://onlinestudylist.com/mailman/listinfo/ccie_rs
>>> _______________________________________________
>>> For more information regarding industry leading CCIE Lab training, please
>>> visit www.ipexpert.com
>>> 
>>> Are you a CCNP or CCIE and looking for a job? Check out
>>> www.PlatinumPlacement.com
>>> 
>>> http://onlinestudylist.com/mailman/listinfo/ccie_rs
>> _______________________________________________
>> For more information regarding industry leading CCIE Lab training, please 
>> visit www.ipexpert.com
>> 
>> Are you a CCNP or CCIE and looking for a job? Check out 
>> www.PlatinumPlacement.com
>> 
>> http://onlinestudylist.com/mailman/listinfo/ccie_rs
> _______________________________________________
> For more information regarding industry leading CCIE Lab training, please 
> visit www.ipexpert.com
> 
> Are you a CCNP or CCIE and looking for a job? Check out 
> www.PlatinumPlacement.com
> 
> http://onlinestudylist.com/mailman/listinfo/ccie_rs
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