====== Handy Cisco Router Commands ======

Originally posted at http://www.nthelp.com/handy_cisco.htm, but that site no longer exists.

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**to add a route:** \\
config t\\
ip route ipaddress subnetmask destination

**to remove a route:** \\
config t\\
no ip route ipaddress subnetmask destination

**to null route an IP address:** \\
config t\\
ip route ipaddress subnetmask null0

**to find a dsl login:** \\
sh user | include xxxxx\\
where xxxxx = either the login name or IP address

**to show interfaces of a certain type quickly:** \\
sh ip int brief | include ATM\\
where ATM can be whatever text identifies the interfaces

**to show how much is blocked by access lists:** \\
sh access-lists

**to find a DSL user on a specific IP:** \\
sh caller ip | include ipaddress

**to reset a DSL user:** \\
clear int vi4.28

**to reinit a DSL user:** \\
config t\\
int atm5/ima2.100 POI (or whatever their interface number is)\\
shut\\
no shut\\
exit

**to track down non-existant dsl user:** \\
config t\\
logging 216.144.x.x  (ip of syslog host)\\
debug pppoe or pppatm or whatever events you need.\\
debug ppp authentication\\
debug vpdn pppoe-events (att or sbc)\\
no debug all (to turn it off)

cle router\\
term mon\\
debug ppp auth\\
debug pppoe event (watch for login and write it down with vpi/vci)\\
no debug all\\
term no mon

**ATM pinging from a cisco:** \\
ping ATM INT a5/ima1.100 vpi vci e\\
Example: ping atm int a5/ima1.100 1 83 e\\
the e means ping endpoint.

[[https://web.archive.org/web/20160908182414/http://www.nthelp.com/tracking_with_cisco.htm|Explains]] how to use a cisco router to track a flood

**columbus- build a dlci based dsl interface** \\
config t\\
int s2/1.136 poi\\
frame-relay interface-dlci 136 IETF\\
exit (once)\\
bridge-group 1

**columbus find user** \\
r-col1#sh arp | include 216.144.63.24\\
Internet 216.144.63.24 18 0010.dcf8.1dd1 ARPA BVI1

r-col1#sh bridge 1 | include 0010.dcf8.1dd1\\
0010.dcf8.1dd1 forward Serial6/0.131 0 627740 172240

lookup dlci 131 in chart

**Access Lists (hssi1/0.500 and hssi2/0)** \\
clear ip access-lists counters\\
sh ip access-lists 152\\
no ip access-group 152 out

**Hung VPDN tunnels** \\
sh vpdn tunnel sum\\
look for wt-ctl\\
sh config and look for atm5/ima1.something\\
config t to shut no shut