Re: ISIS LSP

Guys,

thanx for all the inputs, This is where my confusion comes in...

what about csnp-interval or psnp-interval?

   - Complete sequence number PDUs (CSNPs)Contain a complete list of all
   LSPs in the IS-IS database. CSNPs are sent periodically on all links, and
   the receiving systems use the information in the CSNP to update and
   synchronize their LSP databases. The designated router multicasts CSNPs on
   broadcast links in place of sending explicit acknowledgments for each LSP.
   - Partial sequence number PDUs (PSNPs)Multicast by a receiver when it
   detects that it is missing an LSP; that is, when its LSP database is out
of
   date. The receiver sends a PSNP to the system that transmitted the CSNP,
   effectively requesting that the missing LSP be transmitted. That router,
in
   turn, forwards the missing LSP to the requesting router.

and isis retransmit-interval?

Usage Guidelines

The setting of the *seconds *argument should be conservative, or needless
retransmission will result.

This command has no effect on LAN (multipoint) interfaces. On point-to-point
links, the value can be increased to enhance network stability.

Retransmissions occur only when LSPs are dropped. So setting the
seconds argument
to a higher value has little effect on reconvergence. The more neighbors
routers have, and the more paths over which LSPs can be flooded, the higher
this value can be made.

The value should be higher for serial lines.
 Examples

The following example configures serial interface 0 for retransmission of
IS-IS LSP, every 60 seconds for a large serial line:

interface serial 0

  isis retransmit-interval 60

Regards Splinter

On Sun, Jul 12, 2009 at 8:59 AM, Vinu <vinupeter_at_gmail.com> wrote:

> Thanks Rin,
>
> i guess we can live with it if convergence time is not a constraint... and
> i guess increasing the lsp MTU also will reduce number of LSP packets. in
> the Link... Even though have never worked on real life ISIS network :-(
>
>
>
>
> On Sun, Jul 12, 2009 at 10:32 AM, Rin <rintrum_at_gmail.com> wrote:
>
>> Hi Vinu,
>>
>>
>>
>> The command lsp-gen-interval 120 will increase the latency between
>> consecutive LSP generations. So if we consider in an fix amount of time,
the
>> LSP exchanged will be less. However, this will reduce the convergence time
>> of the network. Thus, Id not use this command for this requirement.
>>
>> Rin.
>>
>>
>> ------------------------------
>>
>> *From:* Vinu [mailto:vinupeter_at_gmail.com]
>> *Sent:* Sunday, July 12, 2009 12:44 PM
>> *To:* Con Spathas
>> *Cc:* Rin; Splinter; Cisco certification
>> *Subject:* Re: ISIS LSP
>>
>>
>>
>> i guess you'll need to add
>>
>>
>>
>> # lsp-gen-interval 120 (it's maximum value in seconds)
>>
>> On Sun, Jul 12, 2009 at 7:00 AM, Con Spathas <ccie19226_at_googlemail.com>
>> wrote:
>>
>> I'd concur with that.
>>
>> I've seen those settings in the IS-IS Network Design Solutions book by
>> Martey/Sturges as well as some DocCD doco...
>> For example:
>>
http://www.cisco.com/en/US/docs/ios/iproute/configuration/guide/isfscbp_ps635
0_TSD_Products_Configuration_Guide_Chapter.html#wp1055077
>>
>>
>> On Sun, Jul 12, 2009 at 2:45 AM, Rin<rintrum_at_gmail.com> wrote:
>> > Hi Splinter,
>> >
>> > I would configure as below:
>> > - specify only L1 or L2 LSP
>> > - Change LSP Remaining Lifetime to maximum value: max-lsp-lifetime 65535
>> > - Change LSP Refresh Interval to maximum value: lsp-refresh-interval
>> 65000
>> >
>> > Just my thought, any other ideas?
>> >
>> > Rin
>> >
>> > -----Original Message-----
>> > From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
>> > Splinter
>> > Sent: Sunday, July 12, 2009 1:20 AM
>> > To: Cisco certification
>> > Subject: ISIS LSP
>> >
>> > Hi,
>> >
>> > I need to make sure that the least number of lsp packets are sent
>> between
>> > routers on a point to point ethernet segment.
>> >
>> >
>> > Thank you
>> >
>> > Splinter
>> >
>> >
>> > Blogs and organic groups at http://www.ccie.net
>> >
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>>
>>
>>
>>
>>
>>
>>
>>
>> --
>> Regards,
>>
>> Vinu Peter
>>
>> CCIE # 16439
>>
>
>
>
> --
> Regards,
>
> Vinu Peter

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Received on Sun Jul 12 2009 - 10:56:43 ART