|
Home > Archive > CCIE > January 2003 > Question about IP Helper-address command
You are viewing an archived Text-only version of the thread.
To view this thread in it's original format and/or if you want to reply to
this thread please [click here]
| Author |
Question about IP Helper-address command
|
|
| haseeb_eng 2003-01-25, 6:54 am |
| Can you check which ip addresses are dynamically assigned to client's machince through ip-helper address command from the Router ? | |
| MadChef 2003-01-25, 7:30 am |
| No, it doesn't have any sort of facility for that. It's really just designed to forward any udp broadcast. bootp/DHCP is just what most people use it for.
MadChef | |
|
| As MadChef said, there is no way of knowing which IPs have been already contacted behind your router through ip helper-address.
There is an alternative awkward way though.
I had the same requirement before for troubleshooting an HP network printer, and the only way you can know which workstation are being contacted behind the router is through "access-list" and "debug"
1) build an access-list like (for example),
access-list 100 permit udp any 10.0.0.0 0.0.0.255 eq 67
access-list 100 permit udp any 10.0.0.0 0.0.0.255 eq 68
(udp 67 is the bootp server, udp 68 is bootpc)
10.0.0.0 is the network being contacted for DHCP offers (You can reverse the ACL, depends on what you wanna see)
2) debug list 110
This way, you will know whats going on there, BUT, as Cisco recommends, DO NOT USE THIS DEBUG COMMAND UNLESS YOU KNOW EXACTLY HOW YOUR ROUTER WILL BE IMPACTED.
Check this link out for more informaiton on BOOTP function with ip helper-address,
http://www.cisco.com/en/US/tech/tk6...
80093fd3.shtml | |
|
| sorry, that should be,
"debug list 100" (not 110)..  | |
| haseeb_eng 2003-01-26, 7:57 am |
| Hi mosam how are you doing man ? Thanks for the tips .  |
|
|
|
|