cdp disable.....

[ohforce55]

Hi,

I'm trying to analyze for the network at the new company.

I noticed that all the routers and switches aren't enabled CDP...

How should I analyze the network in a prompt way and easy way.

I will very appreciate if you can help help me.

Thank you in advance!

[johnd2310]

Hi,

What do you need to analyse on the network? Are you trying to map the topology?

Thanks

John

[ohforce55]

Hi John,

Thanks for your reply.

Yes. There are already diagrams for the network but by only looking at the diagrams, I don't fully understand.. 

I'd like to know what is connected to what and not only that but how IGP and BGP are running and other things if you can advise me.

I will also appreciate what other things I have to look primarily.

Thanks in advance!

[Julio E. Moisa · Accepted solution]

Hi

If CDP is not enabled you could analyze the routing table or protocols, the following links could be useful:

Show ip route
Show ip protocols
Show ip cef
Show ip vrf

If EIGRP:

Show ip route eigrp
show ip eigrp topology

if OSPF

show ip route ospf
show ip ospf database

if BGP

show ip route bgp
show ip bgp summary
show ip bgp
show bgp ipv4 unicast summary
show bgp vrf <vrf name> all summary

Hope it is useful

:-)

[ohforce55]

Hi Julio,

Thank you for your reply!!

I actually know that commands but there are so many routes in each tables....

Since the network is so large, I think it will take some time...

What specific do I have look for those commands?

I assume that you are senior engineer. I know it depends how large the network is, but how long does it usually take for you to analyze all the network when you just start for new company?

Are there any other tips to do or to look at on network devices?

Since I just started, it will be very helpful if you can give me the tips.

I always appreciate for your help Julio!!

[Julio E. Moisa]

You are welcome, 

For example if the IGP is OSPF, you could analyze the LSA's so it can provide you information about the subnets, uplinks and external networks advertised by ASBR routers, remember the routers have the same picture of the network into the same OSPF area. 

Now other tips and they are important to know are: identify the critical applications, the redundancy paths and how they work, verify if QoS is applied on the different network layers starting with access layer, the security applied and talk with the team (if there is) in charge of that area to know the alignments.

I always try to keep a document with the IP plan, it document includes all the networks or IP addresses used for different tasks or projects. 

:-) 

[ohforce55]

Thank you!!!!

[Julio E. Moisa]

It was a pleasure my friend.

Have a great day!

[Joseph W. Doherty]

If you're looking for an "easy" way for a large network, you might investigate tools that perform "network discovery".