Cisco IOS Cookbook, 2nd Edition

Generating a Report of Routing Table Information

Problem

You need to extract the IP routing table from one of your routers.

Solution

The script in Example 2-2, rt.pl, uses SNMP to extract the routing table from a specified router, and displays this information to standard output (STDOUT). The script expects to find a hostname or IP address of a router on the command line.

Example 2-2. rt.pl

#!/usr/bin/perl # # rt.pl -- a script to extract the routing table # from a router. # #Set behavior $snmpro="ORARO"; # $x=0; $snmpwalk="/usr/local/bin/snmpwalk -v 1 -c $snmpro"; $snmpget="/usr/local/bin/snmpget -v 1 -c $snmpro"; chomp ($rtr=$ARGV[0]); if ( $rtr eq "" ) {die "$0: Must specify a router\n"}; print "Destination\tMask\t\tNexthop"; print "\t\t Proto\tInterface\n"; @iftable=\Q$snmpwalk $rtr ifDescr\Q; for $ifnum (@iftable) { chomp (($intno, $intname) = split (/ = /, $ifnum)); $intno=~s/.*ifDescr\.//; $intname=~s/"//gi; $int{$intno}=$intname; } @ipRouteDest=\Q$snmpwalk $rtr ipRouteDest\Q; @ipRouteMask=\Q$snmpwalk $rtr ipRouteMask\Q; @ipRouteNextHop=\Q$snmpwalk $rtr ipRouteNextHop\Q; @ipRouteProto=\Q$snmpwalk $rtr ipRouteProto\Q; @ipRouteIfIndex=\Q$snmpwalk $rtr ipRouteIfIndex\Q; #@ipRouteMetric1=\Q$snmpwalk $rtr ipRouteMetric1\Q; for $intnum (@ipRouteIfIndex) { chomp (($foo, $int) = split (/= /, $intnum)); chomp (($foo, $dest) = split (/: /, @ipRouteDest[$x])); chomp (($foo, $mask) = split (/: /, @ipRouteMask[$x])); chomp (($foo, $nhop) = split (/: /, @ipRouteNextHop[$x])); chomp (($foo, ...