From: Edwards, Andrew M (andrew.m.edwards@boeing.com)
Date: Fri Jan 14 2005 - 19:16:24 GMT-3
I tried using distance for ISIS and had the following results:
1. distance 120 0.0.0.0 255.255.255 <acl>
Performs as expected to match all routing sources and modify distance
for ACL routes
2. distance 120 <neighbor ip> 0.0.0.0 <acl>
Did NOT change the distance for ISIS learned routes by that neighbors
IP. Expected cause its link state.
For my own edification I was unable to find a way to match a routing
source for ISIS (which I sort of understand cause ISIS uses the circuit
identifier for identification). So I wondered how to just change one
route from the routing source and tried this...
3. distance 120 <IP of route to change> 0.0.0.0 <acl>
This changed only that ISIS learned routes distance. Not sure why...
Need to think of it but thought I'd share this anyhow.
Andy
-----Original Message-----
From: Mark Lasarko [mailto:mlasarko@co.ba.md.us]
Sent: Friday, January 14, 2005 1:57 PM
To: swm@emanon.com; ccielab@groupstudy.com; ccie2be@nyc.rr.com
Subject: RE: Distance vs Distance
Greetings Scott, Tim, GS, etc...
1st, It appears there is RIP 'Distance' support in IPv6!
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123cgcr/
ipv6_r/ipv6_04g.htm#wp1841586
"To configure an administrative distance for Intermediate
System-to-Intermediate System (IS-IS), Routing Information Protocol
(RIP), or Open Shortest Path First (OSPF) IPv6 routes inserted into the
IPv6 routing table, use the distance command in address family
configuration or router configuration mode..."
Examples:
ISIS
Router(config)# router isis cisco
Router(config-router)# address-family ipv6 Router(config-router-af)#
distance 199
RIP:
Router(config)# ipv6 router rip cisco
Router(config-router)# distance 199
Very cool :)
Now that 'v6 is fair game I thought it worthy of mentioning.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2nd,
In looking for a solid doc link to the ISIS distance [clns | ip]:For
example:
router isis
distance 115 ipI checked 12.2 @
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/
fapolo_r/clns/3rfclns1.htm#wp1041800
and 12.3 @
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123cgcr/
isocln_r/n5ftrcn1.htm#wp1041800
Only [CLNS] was mentioned?
I finally found an example that mentioned 'ip' in the context of ISIS
distance @
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/
fipr_c/ipcprt2/1cfindep.htm#wp1001842
The educated I guess tells me that this is just another under-documented
anomaly! Only in the configuration guide?
Do you concur??
(Still working on that analogy, Tim - we have to start somewhere!)
Take care y'all,
~M
>>> "Scott Morris" <swm@emanon.com> 1/14/2005 3:59:02 PM >>>
That's an interesting analogy for it all. :)
When you use the retail version, you can have a broad ACL apply to any
neighbor and therefore affect the same change as the wholesale version.
Which do you use? Well, here you lose the analogy. You should be as
specific as possible. Just because you should stay 500 feet back from a
firetruck (per its sign) doesn't mean that you apply that to every
vehicle you are near. Perhaps you do. Like AD, it's your own decision
and doesn't really affect anyone else, but may lead you to make some
less-than-optimal decisions.
As for ISIS, yes there are multiple versions. If you aren't careful,
when you enter "distance isis" and go back to look at your config, you
will find you are only changing distance on isis CLNS routes. There is
also "distance isis ip" which is likely more what you want. But
otherwise, there are no further delineations.
HTH,
Scott Morris, MCSE, CCDP, CCIE4 (R&S/ISP-Dial/Security/Service
Provider)
#4713, JNCIP, CCNA-WAN Switching, CCSP, Cable Communications Specialist,
IP Telephony Support Specialist, IP Telephony Design Specialist, CISSP
CCSI #21903 swm@emanon.com
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
ccie2be
Sent: Friday, January 14, 2005 3:42 PM
To: Group Study
Subject: Distance vs Distance
Hi guys,
Have any of you had difficulty learning when to use the different
versions of this command.
I have but now I think I got it and want to confirm with the pool of GS
brain power.
Several protocols support a version of distance that specific to that
protocol.
For example, distance eigrp, distance ospf, and distance bgp. (Rip and
isis don't seem to have an equivalent)
In addition, there's the plain or IP version of distance <AD#> <ip addr
mask> [acl] command.
The way I think about these now is that the distance <protocol> version
of the command is sort of "wholesale".
It will change the AD for all routes in the route table that match that
protocol (or class) within that protocol.
While the distance <AD#> version of the command is more like "retail".
It will affect those routes that that are either
from a certain neighbor(s) or match the optional acl at the end of the
command.
Q1: Do people agree with this conceptualization?
Q2: Can the same thing be done with ip version of the command that can
be done with the protocol specific version
as long as the neighbors and acl are properly defined?
Q3: Has anyone come up with a simple way of knowing when using the ip
version of the command which ip address to use
when defining the source of the routes? I recall that sometimes it's
the router ID of the neighbor but sometimes the physical
address but can never remember which.
All your thoughts and insights are appreciated.
TIA, Tim
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