cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Announcements
147
Views
0
Helpful
6
Replies
Beginner

Can I log outside dynamic IP address with 871?

I'm looking to clean up some web traffic analysis on a remote server. Can I log the changing outside dynamic IP my router is assigned to?

Everyone's tags (1)
6 REPLIES 6
Rising star

Is the dynamic address being

Is the dynamic address being assigned with DHCP, IPCP or some other method? If it's a DHCP assignment, the router automatically logs these using messages like this one:

Nov 28 21:42:34: %DHCP-6-ADDRESS_ASSIGN: Interface GigabitEthernet0/9 assigned DHCP address 172.23.2.49, mask 255.255.252.0, hostname R1
Highlighted
Beginner

It's DHCP.Looks like Console,

It's DHCP.

Looks like Console, Monitor, Bugger, Count/timestamp, Persistent are all disabled in my current config. (>_<)

Rising star

Well, that certainly sounds

Well, that certainly sounds like a problem. Was the buffer logging disabled, too? ;)

Beginner

LOL! Frackn G so close to F

LOL! Frackn G so close to F.

YES Buffer was also disabled. (>_<)

 

Beginner

This blog post suggests there

This blog post suggests there's some problem with DHCP logging. I followed the link and its describing some kind of applet installation. All over my head.

http://blog.ipspace.net/2009/10/dhcp-client-address-change-detector.html

 

This cisco page describes turning on logging here. Is this what you recommended?

Is this the minimum which won't log too much (all I want is the DHCP)?

https://supportforums.cisco.com/document/24661/how-configure-logging-cisco-ios#Configuration_Overview:

Rising star

You can always count on Ivan

You can always count on Ivan to have the details. I was unaware that the DHCP log only occurred on initial assignment.

If you do decide to use an EEM applet, you don't need to do anything really special with the logging. Just turn it on in the configuration with "logging buffered 262144" (I use a 256KB logging buffer because the default is too small to be useful.)

Another angle to take that might be easier is to use the DDNS functionality of the router with a service like Dyn. This way you always have a hostname you can reference with the current address and can see the history on their web site. This can be configured as follows:

ip ddns update method DDNS_Dyn
 HTTP
  add http://username:password@members.dyndns.org/nic/update?hostname=<h>&myip=<a>;
 interval maximum 90 0 0 0
!
interface GigabitEthernet0/9
 ip ddns update hostname example.dyndns.com
 ip ddns update DDNS_Dyn
CreatePlease to create content
Content for Community-Ad
July's Community Spotlight Awards