From: Carlos G Mendioroz (tron@huapi.ba.ar)
Date: Wed Oct 23 2002 - 19:44:58 GMT-3
Capabilities shown for a neighbour are those "common" to both
local and remote. I would guess that 2 new ciscos will show
both old and new (i.e. standard and cisco's own refresh)
Soft reconfiguration has nothing to do with it as far as
implementation goes. There was a thread some time ago on when
soft reconfig might make sense after/when/if refresh is available.
When ORF is not available, soft reconfiguration can be a good trade
for slow links carrying many routes when/if policy changes are foreseen.
MADMAN wrote:
> Here are the configs of the two routers, just enough to establish BGP,
> nothing more. I also logged into a customer router that shows only
> "new" in the bgp nei output but I can't look at the neighbor router
> unfortuately.
>
> 7507:
>
> router bgp 10
> no synchronization
> bgp log-neighbor-changes
> network 33.0.0.0
> neighbor 172.28.64.9 remote-as 11
> no auto-summary
>
> 7206:
>
> router bgp 11
> bgp log-neighbor-changes
> neighbor 172.28.64.11 remote-as 10
>
> As you can see I haven't configured soft reconfig. Carlos Mendioroz
> sent an interesting email stating that old may refer to a proprietary
> pre standard router refresh though one would think that if both router
> are capable they would negotiate one version, hopefully the standard.
>
> Thanks
>
> Dave
>
> Brian McGahan wrote:
>
>>Dave,
>>
>> I would assume that "old" route-refresh is soft-reconfiguration,
>>and that "new" route-refresh is dynamic route-refresh.
>>
>>I get the following output with 12.1(12) though:
>>
>>Rack8R4#sh ip bgp nei 170.8.2.254 | in refresh
>> Route refresh: advertised and received(new)
>>
>> There is no mention of "old" refresh in the output, and I cannot
>>find a reference on CCO to it. I'll keep you posted if I find out any
>>more info though.
>>
>>Brian McGahan, CCIE #8593
>>Director of Design and Implementation
>>brian@cyscoexpert.com
>>
>>CyscoExpert Corporation
>>Internetwork Consulting & Training
>>Voice: 847.674.3392
>>Fax: 847.674.2625
>>
>>
>>>-----Original Message-----
>>>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
>>
>>Of
>>
>>>MADMAN
>>>Sent: Wednesday, October 23, 2002 2:52 PM
>>>To: Brian McGahan
>>>Cc: Liban.Mohamed@mail.sprint.com; ccielab@groupstudy.com;
>>>rich@myhomemail.net
>>>Subject: Re: bgp soft-reconfig in?
>>>
>>> I take it the route-refresh is the new, (12.1) dynamic inbound soft
>>>reset which requires no new config. (I was checking out the URL you
>>>provided:) So I set up a very basic BGP connection to see if this was
>>>negociated, both routers are running 12.2xx but I'm not sure what this
>>>output is saying and can't find it on CCO:
>>>
>>>C7206VXRB#sh ip bgp nei
>>>BGP neighbor is 172.28.64.11, remote AS 10, external link
>>> BGP version 4, remote router ID 172.28.64.11
>>> BGP state = Established, up for 00:00:13
>>> Last read 00:00:12, hold time is 180, keepalive interval is 60
>>
>>seconds
>>
>>> Neighbor capabilities:
>>> Route refresh: advertised and received(old & new)
>>>
>>> What is the "Route refresh: advertised and received(old & new)"? I
>>>assume the routers have negociated that they are capable of dynamic
>>>reset, what is the old and new??
>>>
>>> Thanks
>>>
>>> Dave
>>>
>>>
>>>Brian McGahan wrote:
>>>
>>>> Soft-reconfig and route-refresh are two different
>>>
>>technologies.
>>
>>>>They both accomplish pretty much the same thing, however they are
>>>>implemented differently.
>>>>
>>>>
>>>
>>http://www.cisco.com/en/US/products/sw/iosswrel/ps1831/products_configur
>>
>>>>ation_guide_chapter09186a00800d97fc.html#xtocid9
>>>>
>>>> Route-refresh is preferable over soft-reconfig, since there
>>>
>>is
>>
>>>>no additional configuration required, and it does not require any
>>>>additional memory resources. Soft-reconfig inbound can be dangerous
>>>
>>to
>>
>>>>use on a production BGP router, since inbound updates must be first
>>>>cached, attributes applied, then flushed from memory. This means
>>>
>>that
>>
>>>>if your router is short on memory, it could crash.
>>>>
>>>> For those of you with access to the Partner E-Learning
>>>>connection, check out this link on multiprotocol extensions for BGP.
>>>
>>It
>>
>>>>gives a good overview of route-refresh and ORF.
>>>>
>>>>http://cisco.partnerelearning.com/pec/trnevtdtl.asp?EvtID=39137
>>>>
>>>>HTH
>>>>
>>>>Brian McGahan, CCIE #8593
>>>>Director of Design and Implementation
>>>>brian@cyscoexpert.com
>>>>
>>>>CyscoExpert Corporation
>>>>Internetwork Consulting & Training
>>>>Voice: 847.674.3392
>>>>Fax: 847.674.2625
>>>>
>>>>
>>>>>-----Original Message-----
>>>>>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On
>>>>
>>Behalf
>>
>>>>Of
>>>>
>>>>>Liban.Mohamed@mail.sprint.com
>>>>>Sent: Sunday, October 20, 2002 2:47 PM
>>>>>To: ccielab@groupstudy.com; rich@myhomemail.net
>>>>>Subject: RE: bgp soft-reconfig in?
>>>>>
>>>>>The dynamic inbound soft reset capability was added to
>>>>>Cisco's BGP support in Cisco IOS Software Release
>>>>>12.0(6)T. BGP Soft Reset Enhancement is supported on
>>>>>most Cisco router platforms up through the Cisco 7500
>>>>>Series routers. Soft resets can be initiated without extra
>>>>>commands using only the clear ip bgp in command.
>>>>>
>>>>>
>>>>>Basically soft reconfiguration is to gracefully allow policies to
>>>>
>>be
>>
>>>>>configured and activated without "hardsetting" the bgp session.
>>>>
>>There
>>
>>>>>are
>>>>>two kinds. Outbound and inbound. For inbound, all recieved routes
>>>>
>>are
>>
>>>>>stored
>>>>>regardless of the fact whether they are accepted or denied. When
>>>>
>>we
>>
>>>>>clear
>>>>>bgp with soft in, the polices are applied on the stored received
>>>>
>>path.
>>
>>>>>When we do clear bgp soft out, all entries in bgp table are re-run
>>>>
>>and
>>
>>>>>new
>>>>>updates are generated to be sent out.
>>>>>syntax:
>>>>>1. sh ip bgp neighbor <peer address> received-routes
>>>>>This displays all the received updates from neighbor
>>>>>2. neighbor <address> soft-reconfiguration <in>
>>>>>This will start storing the received updates. So required for
>>>>
>>INBOUND
>>
>>>>>soft
>>>>>reconfig. Outbound reconfig does not need anything to be
>>>>
>>configured.
>>
>>>>>
>>>>>
>>>>>
>>>>>Thanks,
>>>>>
>>>>>
>>>>>Liban Mohamed
>>>>>IP Engineer
>>>>>Sprintlink Internet BackBone
>>>>>www.sprint.net
>>>>>
>>>>>-----Original Message-----
>>>>>From: rich [mailto:rich@myhomemail.net]
>>>>>Sent: Sunday, October 20, 2002 2:56 PM
>>>>>To: ccielab
>>>>>Cc: rich
>>>>>Subject: bgp soft-reconfig in?
>>>>>
>>>>>
>>>>>Is it true, when the neighbors support;
>>>>>
>>>>>Neighbor capabilities: (taken from sho ip bgp neighbor)
>>>>> Route refresh: advertised and received
>>>>> Address family IPv4 Unicast: advertised and received
>>>>>
>>>>>that you don't need to use the neighbor x.x.x.x
>>>>
>>soft-reconfiguration
>>
>>>>>inbound command? I have not used this command once. After making
>>>>
>>a
>>
>>>>>change to my bgp I just do a clear ip bgp XX sof.
>>>>>
>>>>>
>>>>>Rich
>>>>
>>>--
>>>David Madland
>>>CCIE# 2016
>>>Sr. Network Engineer
>>>Qwest Communications
>>>612-664-3367
>>>
>>>"You don't make the poor richer by making the rich poorer." --Winston
>>>Churchill
>>
>
-- Carlos G Mendioroz <tron@huapi.ba.ar> LW7 EQI Argentina
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