Cisco Layer 3 Switch Integration Script (3750X)
This document provides scripts required to complete the installation of the NAC Solution
NAC Router Integration Script
In order for policy-based routing to work on the 3750Xs, you will need to ensure that it is configured to use the “desktop dual IPV4 and IPV6 routing template”. Information can be found at:
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750/software/release/12-2_55_ se/configuration/guide/scg3750/swsdm.html
To check which template is currently configured on the 3750Xs, please issue the following command:show sdm preferIf the current template is not the “desktop dual-ipv4-and-ipv6 routing” template, you will need to change the template and reload the switches.Please run the script below if the routing template needs to be changed: conf t!sdm prefer dual-ipv4-and-ipv6 routing desktop!reloadOnce the switch has booted, please issue the following command: show sdm preferThe switches should now show the “desktop dual-ipv4-and-ipv6 routing” template in use.Please proceed with the script on the following page once the routing template has been verified on the switches.
conf t!flow record sc-record match ipv4 version match ipv4 tosmatch ipv4 ttl match ipv4 protocolmatch ipv4 source address match ipv4 destination address match transport source-portmatch transport destination-portcollect counter bytes collect counter packets collect timestamp sys-uptime firstcollect timestamp sys-uptime last!flow exporter sc-exporterdestination x.x.x.x (replace x.x.x.x with IP of NAC server and remove this comment)transport udp 50001!flow monitor sc-monitor exporter sc-exporter record sc-recordcache timeout active 60!ip access-list extended impulse_block permit ip any host 198.31.193.211!ip access-list extended intranet remark allow DNSpermit udp any any eq domain remark allow DHCPpermit udp any any eq bootps remark allow access to AD serverpermit ip any host x.x.x.x (Replace with IP of AD server and remove this comment)remark allow access to AV serverpermit ip any host x.x.x.x (Replace with IP of AV server and remove this comment)remark allow RDP access to blocked hosts permit tcp any eq 3389 any!route-map impulse permit 10match ip address intranet! route-map match ip impulse address permit 20 impulse_blockset ip next-hop x.x.x.x (replace x.x.x.x with IP of NAC server and remove this comment)!int X (Layer 2 interface(s) for any layer 3 interface with the redirect-group applied, remove this comment)ip flow monitor sc-monitor inputinterface X (Layer 3 interface(s) which is/are default gateway for subnet(s) to be placed under policy – recommend a test subnet first, remove this comment)ip policy route-map impulseip helper-address x.x.x.x (replace with IP of NAC appliance and remove this comment)!end*Note – Be sure to also allow the NAC Enforcer access to the router if a VTY/SSH access-list is present on the router.
