Cisco IOS: Ether-Channel Trunks
Apr08

Cisco IOS: Ether-Channel Trunks

KB ID 0001533 Problem This is a subject that every time I need to create an Ether-Channel I end up checking beforehand, so it’s about time I wrote it up. We are combining two different things, an Ether-channel, (an aggregation of links) and a Trunk (the ability to carry many VLANS). If you are NOT from a Cisco background then you might want to read though the following post first to avoid confusion about the world...

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Cisco ASA VPN to Cisco Router “MM_WAIT_MSG3”
Mar27

Cisco ASA VPN to Cisco Router “MM_WAIT_MSG3”

KB ID 0001531 Problem While migrating a VPN tunnel from an ASA 5520 firewall to a new 5516-X I got this problem. The other end was a Cisco router (2900). As soon as I swapped it over, it was stuck at MM_WAIT_MSG3, and phase 1 would not establish; NUFC-ASA5516x(config-tunnel-ipsec)# show crypto isa IKEv1 SAs: Active SA: 6 Rekey SA: 0 (A tunnel will report 1 Active and 1 Rekey SA during rekey) Total IKE SA: 6 1 IKE Peer: 1.1.1.1 Type :...

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Cisco Error ‘%PHY-4-SFP_NOT_SUPPORTED’
Sep13

Cisco Error ‘%PHY-4-SFP_NOT_SUPPORTED’

KB ID 0001347 Dtd 13/09/17 Problem This is another question I see getting asked a lot in forums! You see something like the following; 000032: *Sep 28 09:35:32.507 UTC: %PHY-4-SFP_NOT_SUPPORTED: The SFP in Gi3/0/50 is not supported (PNL-3750-Stack) 000033: *Sep 28 09:35:32.507 UTC: %PM-4-ERR_DISABLE: gbic-invalid error detected on Gi3/0/50, putting Gi3/0/50 in err-disable state (PNL-3750-Stack) The usual response is ‘Enable...

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Setup RANCID and ViewVC (Part Two) Adding Cisco Devices
Jul28

Setup RANCID and ViewVC (Part Two) Adding Cisco Devices

KB ID 0001332 Dtd 23/07/17 Problem Before on Part One we setup our RANCID and ViewVC server ready to start backing up our devices, now we will look at adding the devices, and automating the backup process. Solution To add a Cisco device you need to do TWO things*. Firstly you need to add and entry in the ‘router.db’ file that lives in the ‘Group’ folder you created back in part one. Secondly you need to add the...

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Setup RANCID and ViewVC (Part One)
Jul21

Setup RANCID and ViewVC (Part One)

KB ID 0001331 Dtd 19/07/17 Problem There are couple of good posts out there on setting up Rancid (Really Awesome New Cisco Config Differ). Some even show you how to set it up with ViewVC (Formally ViewVCS, basically a nice web based GUI front end, that does version control and highlights differences). It does this using a system called CVS (Concurrent Version System, hence the original name.) Then I had to do some more searching to...

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Cisco – Joining Layer 2 Networks Over Layer 3 Networks
May22

Cisco – Joining Layer 2 Networks Over Layer 3 Networks

KB ID 0001313 Dtd 22/05/17 Problem It’s a common problem, you want to connect one site to another and still have them on the same layer 2 network. As you can see above both the routers at the bottom are in the 172.16.1.0/24 network, let’s assume they are clients in the same layer 2 network how would you connect them? Solution Option 1: xconnect over L2TP All the ‘heavy lifting’ is done on the SiteA and SiteB...

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