Feb
15
The leading question: "Is it possible (and if so, how) to redistribute or originate a default route based on time of day?" The short answer is "Sure, why not?"...  But the longer answer has to do with how do we warp the forces of the universe to make that happen??? Well, start with what we know.  We know we can do time-ranges in access-lists, right?  Can we do them in standard access-lists (what we see used for redistribution all the time)? Rack1R1(config-if)#exit Rack1R1(config)#access-list 1... Read More
May
02
A voice lab rack usually utilizes dedicated piece of hardware to simulate PSTN switch. Commonly, you can find a Cisco router in this role, with a number of E1/T1 cards set to emulate ISDN network side. It perfectly suits the function, switching ISDN connections between the endpoints. Additionally, it is often required to have an “independent” PSTN phone connected to the PSTN switch, in order to represent “outside” dialing patterns - such as 911, 999, 411 1-800/900 numbers. The most obvious way... Read More
Feb
15
Quite many people don't pay attention to the difference in handling packets on interfaces configured for NAT inside and outside. Here is an example to demonstrate how NAT "domains" interact with routing. Consider three routers connected in the following manner: Read More
Jan
25
Sometimes people need to conditionally advertise routes into BGP table based on time of day. Say, we may want to adversite IGP prefix 150.1.1.0/24 with community 1:100 during daytime and with community 1:200 at the other time. Back in days, the procedure was easy - you had to create time based ACL, and use it in route-map to set communities: Read More

Subscribe to INE Blog Updates

New Blog Posts!