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What is Local <acronym title="Policy-Based Routing">PBR</acronym>?
Policy-based routing makes routing decisions based on factors other than normal routing protocols. For example, it might be necessary to forward all <acronym title="Session Initiation Protocol">SIP</acronym> packets via a more expensive low-latency link while all other traffic use …
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Today I was browsing through the Cisco NetPro Forums and came across someone that needed to track down which switch port a <acronym title="Media Access Control">MAC</acronym> address had been dynamically learned on.
I'd seen this sort of thing before in the Bridge MIB, so I assumed it …
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By default Point-to-Point Tunneling Protocol (PPTP) will now work properly through a Cisco Adaptive Security Appliance (ASA) firewall or it's forerunner the Cisco <acronym title="Private Internet EXchange">PIX</acronym>.
Prior to PIX software version 6.3, allowing PPTP to work through a PIX was a painful procedure involving static …
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The following are the Peer-to-Peer (P2P) protocols recognized by Cisco's NBAR Protocol Discovery.
If I've missed any, leave a comment below or use the Slaptijack Contact Form to update me.
Thanks!
Posted on in Networking
You'll find that some network problems can only be solved by sticking a packet sniffer on the network and seeing what the packets are doing. In a switched environment, this will not work properly since each port is configured to only broadcast traffic destined for the MAC addresses it has …
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One of my pet peeves is Cisco switch and router interfaces that remain unlabeled. There is nothing worse that trying to debug a network problem when the problematic interface is unlabeled. Instead of spending valuable time working on the actual problem, you've got to trace down where this cable goes …
Posted on in Networking
I've been in the situation before were I needed to discover the neighbors of a Cisco device programmatically. This is useful in a case where you want to crawl a network without hard-coding a list of devices into your script. By default, all Cisco devices have Cisco Discovery Protocol (CDP …
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If you are at all familiar with <acronym title="Simple Network Management Protocol">SNMP</acronym>, you've probably heard of "community strings". Community strings are similar to passwords. They define and grant access to a device's <acronym title="Management Information Base">MIB</acronym>. If you've used SNMP in conjuction with a …
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You might have a situation where you have multiple network segments utilizing <acronym title="Dynamic Host Configuration Protocol">DHCP</acronym> to assign IP addresses, name servers, etc. DHCP clients use network broadcasts to alert a DHCP server to their presence. Once a request for an address has been made, the …
Posted on in Networking
This isn't late breaking information, but there's an interesting post in the Cisco WAN, Routing and Switching Forum regarding a particular regular expression that, when used in conjunction with the show ip bgp regexp, results in a router crash. Here is the full command.
show ip bgp regexp (.*)(_\1 …
