Posted on in Networking
I recently had the pleasure of working on a client's Cisco 2600 series router that had not been used in quite some time. Access lists on the vty lines and a misconfigured con line meant I was locked out. In a situation like this, the only way to gain access …
Posted on in Networking
By default, service set identifiers (SSIDs) configured on a Cisco integrated services router are not broadcast. This means that if you want to configure a client to use the wireless network, you'll have to manually enter the SSID in the client configuration. This isn't a bad thing, but it is …
Posted on in Networking
Laurence F. Sheldon, Jr. just gave a great cable tag definition on the NANOG mailing list.
The tags should have a short (two or three word) description, the authority for the patch (person's name or position, order number, or trouble ticket number) and where the [other]{.underline} end of the …
Posted on in Networking
As you might recall, I had previously taken umbrage with Cisco's inability to forward a range of ports to a particular host. Many readers have offered suggestions and links to other documents around the Internet offering various solutions, but none of them really sat quite right with me.
In hindsight …
Posted on in Networking
I've written a lot of posts about various methods for blocking <acronym title="Peer-to-Peer">P2P</acronym> traffic, especially with Cisco's Network Based Application Recognition (NBAR). Although these posts are probably of interest to smallish Internet Service Providers and administrators of business networks, they don't have much use for the average …
Posted on in Networking
Error: The image in the archive which would be used to upgrade
Error: system number 1 does not support the same feature set.
I just got this error message while upgrading a Cisco Catalyst 3560 from 12.2(35)SE5 to 12.2(44)SE. The older version was IP …
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Oops! I guess I'm way behind the times.
For quite a while, I've been using ip verify unicast reverse-path to prevent packets with spoofed source addresses from crossing my routers. Apparently, as of IOS 12.0 (12.4 is current as of this writing), that command has been replaced with …
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"How do I find a Cisco serial number remotely through the command line?"
This is one of those frequently asked questions that I see over and over. So, here's the quick and dirty answer:
You can find Cisco serial numbers from the IOS command line by using the
show inventory …
Posted on in Networking
I've talked about using Cisco <acronym title="Network-Based Application Recognition">NBAR</acronym> frequently (check the Related Posts section below for more articles). One thing I've never pointed out is that not all versions of Cisco <acronym title="Internetwork Operating System">IOS</acronym> come with all protocol descriptions built in.
Not …
Posted on in Networking
When setting up a Cisco ASA or PIX to send logs to a remote syslog server, you need to specify which facility to use. This can cause a bit of disconnect since the syslog server configuration uses names and the logging facility command in the Cisco Adaptive Security Appliance Software …
