I’m an awful sysadmin. Running services permanently isn’t really my forte, I tend to lean more on the “I’ll get this proof of concept all working, prove that it works or doesn’t, then roll it on for polishing by someone else” kinda guy. That final 15% is something I’m constantly working to refine and better myself at accomplishing. I’m decent at debugging network services, and can be handy in a “oh crap, it’s down!

Let me save you some time….Microflow Policing on the Catalyst 6500 / Sup2TXL doesn’t yet work. Inbound it “kinda works”. You can configure it and it applies as a service policy, but even though outbound is “supported in hardware on the Supervisor2TXL”, there is no software support for it in either the 15.0SY or 12.2(50)SY. It took me a month to suss this out….. Yes, I should have suspected. I dont work on Cisco every day, I have Juniper MX, Brocade MLX and a multitude of other platforms to work on daily, so it took a bit.

I’ve been doing research, carrier and service provider networking for a long time. I my first real service provider experience was beta testing DSL for GTE back in the 1990s, I prototyped and proposed a CLEC for an employer in 1998 and went to work for the only ISP in the area rolling it’s own DSL over ATM in early 2000. Everything seems to come full circle, though, given enough time.

Data centers are one of the hot things in networking tech right now. Combine SDN, cloud, buzzword of the day, mix with data center and serve over ice. I end up doing a lot with data centers for whatever reason. This, however, is something I found interesting. “DCTCP is an enhancement to the TCP congestion control algorithm for data center networks. It leverages Explicit Congestion Notification (ECN), a feature which is increasingly becoming available in modern data center switches.

I’ve recently been tasked with bringing up a tertiary path into a multi-building research facility.

Lets just say, for instance, that you have an MX series router at somewhere on your network. Lets also say that said router is carved into more than just the main logical system. For the sake of this writing, lets say that your eBGP sessions are in the default logical system and your IGP is in the logical system, lets call it “internal”. JunOS has some wonderful mechanisms for keeping things running, one is called NSR (Non Stop Routing), the other is called ISSU (In Service Software Upgrade).

I’ve been looking at iMessage from time to time as my schedule permits, for some reason that I can’t really explain I’m fixated on it. So, just like I did with FaceTime, I started doing network sniffing to see just what it’s doing. The results were not terribly unexpected.  iPhone.buraglio.com.53140 > st11p01st-courier143-bz.push.apple.com.5223: Flags [R], cksum 0x5ec8 (correct), seq 4109691913, win 0, length 0 14:07:51.665485 IP (tos 0x20, ttl 49, id 11699, offset 0, flags [DF], proto TCP (6), length 64, bad cksum 0 (->8fc7)!

Chekkera Gowtham - Feb 2, 2012 This is good stuff. Is it ok if I pick some content up from here for my blog which in on Wan Optimization? Do you have any reservations? Or terms?

I’ve had a co-located server in one way or another for the last 11 years. From hosting a bare metal box at the ISP I worked for for a while, to sharing a bare metal box at a colo provider to switching to a VPS service, I’ve always had an “offsite box”. I just wanted to post a quick “these guys are great” comment to my current VPS provider, ARP Networks.

Janice Clements - Dec 4, 2011 Well there might be something you can do besides the default apple Mail.app. You might want to consider other alternatives. PC Fix Anita - May 4, 2012 It’s good to know that you are always backing up your emails and other data. That’s a good practice which I also always do. I don’t use Mac, but I’ve heard the same problems from some users. Anyway, it’s good that you were able to figure it out.