As promised, here’s some posts from other network blogs that were submitted (some people submitted their site instead of an article, so I picked one). In no particular order:

Understanding OSPF Default Route Generation
Récupère les infos de tes routeurs Cisco avec un super script TCL (Retrieve information about Cisco routers with a super TCL script - Translate to English
Route Summarization
Network Redundancy, Integrity and Reliability…Oh My!
QoS Classification in a Nutshell

Thanks to those that sent me a link, and please repost the above list on your blog so that others can find all these great sites!

I’ll do this again next Sunday, so drop me a link to an article by next Saturday evening.

Recently I’ve been spending a lot of time dealing with Quality of Service (QoS) for voice, so this article will be an introduction to the topic.

QoS involves giving better treatment to some traffic at the expense of others. It’s not going to make any more data fit on the pipe, it just tries to make all the applications happy. Take for instance VoIP and FTP. VoIP needs only a bit of bandwidth (<100Kbit/sec for a G.711 call), but if there is jitter (variation in latency) the call suffers. FTP doesn't care about delay or latency, it'll take as much of the pipe as it can handle (or is constrained because of TCP windowing). Here, the goal of QoS would be to make sure the voice gets the jitter control it needs. If we added in another application such as a CRM tool, we might give bandwidth guarantees to it such that voice gets the priority treatment, CRM gets enough bandwidth to do what it needs, and FTP gets the rest. We could also limito FTP. Such are the decisions necessary when designing QoS policies.

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I was going through my feeds this morning and realized I’m up to 4 other Cisco related blogs (see sidebar), not to mention a few other blogs that occasionally post networking related stuff. This is great! I’ve learned a lot of great tips by reading these blogs, and through my own writing, have talked to many interesting people. So, I have a proposal.

If you have a blog, send me a link to a favourite recent post of yours by Sunday May 14, 2006. The only restriction is that it has to be networking related (ie you don’t have to have a Cisco blog). On Sunday evening I’ll make a post with links to all of them. If you sent me a post, I’d appreciate your reciprocating by posting the list to your own blog.

This isn’t an original idea, I’ve seen it done on other blogs. But it’s an effective method of cross promotion, and brings other visitors that might not otherwise have known about your blog. If it works for all of us, we can do this every couple of weeks, choose topics, etc.

Please share your ideas or links in the comments.

Multilink PPP is an add on to PPP encapsulation that lets you bond multiple links into one. It can be used over asynchronous dialup to bond multiple modem or ISDN connections, or to bond multiple synchronous serial lines such as T1s.
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Due to my own laziness, I let my CCNP expire over a year ago, which means I have to start at the bottom. I finally passed the CCNA today.
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Turns out we had a bad CSU/DSU on a T1 link recently, the thing that made it more difficult was that it was internal to the router (WIC-1DSU-T1)

Troubleshooting serial links is done by testing different parts of the links by looping endpoints.

The basic procedure:
http://www.cisco.com/en/US/tech/tk713/tk628/technologies_tech_note09186a00800a754b.shtml

The difference between loopback dte, loopback remote, and loopback line with pictures.

http://www.cisco.com/en/US/products/hw/routers/ps233/products_tech_note09186a0080093c56.shtml

How to reset the CSU:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1826/products_configuration_guide_chapter09186a00800d9b62.html#xtocid22

I’m a self professed Cisco bigot. I use the term “bigot” because that’s what the Nortel sales guy called me and the name stuck. I’ve also heard the term “customer evangelist” thrown around by marketing people — a customer who is happy with the company, and tells others about it.

Why do I willingly pay twice the price (granted, it’s not my money) for the same hardware? The answer is support.
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It’s rare that I open a case with TAC, I’m usually able to figure things out with the help of the docs or by working at it. But this past week, I’ve been involved with several cases:

Upgrade problems - After swapping the flash in a 3660, we couldn’t store an image on the new flash via xmodem. The solution ended up being for us to copy the image to DRAM, boot to that, format the filesystem, then copy the image to flash
ATM problems - After the upgrade, ATM failed. Turns out there’s a bug in the version we were upgrading from that enabled ATM payload scrambling no matter what the config said. After the upgrade, it respected the config, turned scrambling off, which meant the router couldn’t talk to its peers. See: http://www.cisco.com/en/US/tech/tk39/tk49/technologies_tech_note09186a00800d73b7.shtml#knownissue_atm_scramble
CiscoWorks won’t sync archive - Even though my CW2K server could log in to all the devices, it couldn’t pull down the configs. I still don’t understand why, but after telling CW2K to use TFTP it worked. I still ran into a bug where many switches are shown as “partial failures” because of a bug in CW2K, even though it succeeded.
CiscoWorks Netconfig jobs don’t work on switches - Still going through this one with TAC. I can run a netconfig job on routers just fine, but not on switches
policy-map editing hangs the exec session - after the above upgrade, whenever I try to create or edit a policy-map, the exec session hangs. I just opened the case on this one.

I also noticed that the CPU on the router climbed about 10%, might need a case on that to help investigate.

I got a call from someone in the company yesterday whose husband is getting retrained and is considering a career in netword administration. They asked if I could meet with him to tell him about the career. I’m happy to, but what do I say?

Netword admin is such an inaccurate term. In both the places I’ve worked so far the network guys end up having their hands in everything because they’re the ones with the most aptitude for figuring things out. I mean three weeks ago our Notes server died and with four server guys watching us, the network guys rebuilt it. Just because it ran Linux and it was outside their comfort zone.

People often joke that my kids were probably born with a router in their hands, but I often think they should do something else. This is probably a standard parental desire to want better for one’s offspring, but would I wish this career on another? After alll, I can’t imagine doing anything else.

Just testing posts from the blackberry. I seem to get good ideas on the way to and from work, maybe posting them immediately will help!