about 1 year ago - 16 comments
Here’s a handy list of ACL entries to allow your devices to speak routing protocols, availability protocols, and some other stuff. We’ll assume you have ACL 101 applied to your Ethernet inbound; your Ethernet has an IP of 192.168.0.1.
BGP : Runs on TCP/179 between the neighbors
access-list 101 permit tcp any host 192.168.0.1 eq 179
EIGRP More >
about 1 year ago - 1 comment
My friend Josh over at blindhog.net has found a collection of cheat sheet gems for the network dude(tte). There’s sheets on BGP, OSPF, Subnetting, QoS, connector types, and more. Check it out.
Cheat Sheets – Packetlife.net
about 1 year ago - 2 comments
Here’s a scenario I ran into long ago. We had several sites that had a frame relay link back to headquarters and a DSL line. Each link was terminated into a different router on a flat LAN with the users. The DSL was for Internet access, but also terminated a VPN as More >
about 1 year ago - No comments
If you’re running iBGP, you may have run across this. What if you had three routers — R0, R1, R2 — that were running BGP under the same ASN, but R1 and R2 weren’t peered? Any routes coming from R1 would not show up on R2 and vice versa. iBGP, by standard, More >
about 1 year ago - No comments
I realized the other day that I haven’t mentioned EIGRP once. As a Cisco guy, I think I’m required to do at least one article on it, so here it goes.
Enhanced Interior Gateway Routing Protocol (EIGRP) is a Cisco-proprietary routing protocol. Routing protocols share routes, right, but “interior” is the keyword here; it’s More >
about 1 year ago - 1 comment
HSRP (Hot Standby Router Protocol) is a Cisco-proprietary method for supplying a highly-available gateway for hosts to use. GLBP (Gateway Load Balancing Protocol) does the same thing. So, what’s the difference?
HSRP works on layer 3 and provides a standby IP address for hosts on that network to use as their gateway (or other More >