Solved

Cisco Show ip route question

Posted on 2014-10-10
4
270 Views
Last Modified: 2014-10-19
I have some fail over routing in place on my Cisco 2921 voice router and i am trying to figure out where it is coming from.
First thing i have never seen the route Type code of 'L' before. Second thing i am not sure why the /32 L routes are showing up i only have the ip addresses defined on the interfaces with a /24.

Any insight would help as i think what ever is causing this may be the route of my Dynamic fail over isn't working.


S*    0.0.0.0/0 [130/0] via 172.31.105.1
      172.21.0.0/16 is variably subnetted, 4 subnets, 2 masks
C        172.21.1.0/24 is directly connected, GigabitEthernet0/0.1
L        172.21.1.1/32 is directly connected, GigabitEthernet0/0.1
C        172.21.2.0/24 is directly connected, GigabitEthernet0/0.100
L        172.21.2.1/32 is directly connected, GigabitEthernet0/0.100
      172.31.0.0/16 is variably subnetted, 2 subnets, 2 masks
C        172.31.105.0/24 is directly connected, GigabitEthernet0/1
L        172.31.105.2/32 is directly connected, GigabitEthernet0/1
0
Comment
Question by:Steve262
  • 2
4 Comments
 
LVL 28

Accepted Solution

by:
Predrag Jovic earned 333 total points
ID: 40374047
L - means local ip address
/32 means just this IP address
172.21.1.1/32 is directly connected, GigabitEthernet0/0.1
In newer versions Cisco IOS Version 15.0(1)S and Cisco IOS-XR Version 4.3.1 has introduced L - local (I guess it is because of local link addresses of IPv6).
More:
http://www.cisco.com/c/en/us/support/docs/ip/ip-routing/116264-technote-ios-00.html
Sometimes you can have problems (in some configurations) if you have ip address on interface, and have subinterfaces configured (frame relay). And you have that in your configuration, but it also may mean nothing.
0
 
LVL 18

Assisted Solution

by:Akinsd
Akinsd earned 167 total points
ID: 40374998
C        172.21.2.0/24 is directly connected, GigabitEthernet0/0.100  
The Network 172.21.2 is directly connected to Gig0/0.100

 L        172.21.2.1/32 is directly connected, GigabitEthernet0/0.100
The Local IP address on GIG0/0.100 is 172.21.2.1
As mentioned by Lovic, /32 refers to a single host.

Directly connected routes take precedence over static or learned routes as their AD is 0 (Default for Static is 1 or whatever AD value you assign to it)

Do a show run route, or show run | section ip route or just show run, and scroll down to the ip route section and post the result.
Static redundant routes will not show in the route table until the primary route fails. Post the show run (route section) and we'll go from there
0
 

Author Comment

by:Steve262
ID: 40381060
So i think what you guys are saying is this is just an idiosyncrasy of IOS 15.0 or above and that is why it may stand out compared to  what i have seen in the past.  

I am running OSPF on the router and using Weighted Static routes for fail over. I think there may be a separate issue entirely. I am assuming that both the local host directly connected route and the Directly connected network will go down if the link goes down. Correct?
0
 
LVL 28

Assisted Solution

by:Predrag Jovic
Predrag Jovic earned 333 total points
ID: 40381478
IOS 15.0 or above and that is why it may stand out compared to  what i have seen in the past.

Yes
I am assuming that both the local host directly connected route and the Directly connected network will go down if the link goes down. Correct?
In some cases yes, but it is not necessarily so, cable modem usually keeps directly connected network alive even if network behind cable modem is dead. So, that depends on design.
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Join Greg Farro and Ethan Banks from Packet Pushers (http://packetpushers.net/podcast/podcasts/pq-show-93-smart-network-monitoring-paessler-sponsored/) and Greg Ross from Paessler (https://www.paessler.com/prtg) for a discussion about smart network …
If you're not part of the solution, you're part of the problem.   Tips on how to secure IoT devices, even the dumbest ones, so they can't be used as part of a DDoS botnet.  Use PRTG Network Monitor as one of the building blocks, to detect unusual…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
Here's a very brief overview of the methods PRTG Network Monitor (https://www.paessler.com/prtg) offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…

828 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question