Acl
AS-Path Filtering
- Tony Mattke
- Routing
- 4 min read
Before we get into the how, let’s talk about the why. According to the CIDR Report, the global IPv4 routing table sits at about 525,000 routes, it has doubled in size since mid …
Using Deny ACEs in your PBR ACL on your Nexus 7k
- Tony Mattke
- Switching
- 1 min read
Quite a while ago I had a need for some network duct tape… Policy Based Routing while useful should only IMHO be used as a temporary fix. But as you know, temporary things soon …
Time-based ACLs
- Tony Mattke
- Security
- 2 min read
Ever since Cisco released IOS 12.0.1T we’ve had the ability to broaden the reach of the extended ACL to allow the influence of time. Time-based ACLs reference a time range that is …
Using Discontiguous Wildcard Masks in ACLs
- Tony Mattke
- Switching
- 5 min read
Unlike subnet masks, wildcard masks allow you to use discontiguous bits which enable you to match on a range of values. Using these within routing protocols is typically frowned …
IOS ACL Resequencing
- Tony Mattke
- Security
- 4 min read
This is one of those tricks you wish you learned about 10 years ago, but never did. You know how easy it is to mess up a nice looking access list. You get one setup on the router, …