Re: Question about peering
At the previous regional ISP i worked for we peered with google, facebook, yahoo, pandora and several other content providers at Any2 exchange (coresite). We capitalized on that link since a tremendous amount of our traffic was destined for those networks. The cost to join that exchange was relatively cheap compared to what we were paying for transit. You may want to look for a similar exchange at your pop. On Thu, May 10, 2012 at 9:23 AM, Justin Wilson wrote: >We are cross-connected with several ISPs at a couple of data > centers. > Very helpful in one situation as several of us share a soft-switch. > >Justin > > -Original Message- > From: Rob Szarka > Date: Wednesday, May 9, 2012 4:50 PM > To: > Subject: Re: Question about peering > > >On 4/6/2012 3:11 PM, Anurag Bhatia wrote: > >> I am curious to know how small ISPs plan peering with other interested > >> parties. E.g if ISP A is connected to ISP C via big backbone ISP B, and > >>say > >> A and C both have open peering policy and assuming the exist in same > >> exchange or nearby. Now at this point is there is any "minimum > >>bandwidth" > >> considerations? Say if A and C have 1Gbps + of flowing traffic - very > >> likely peering would be good idea to save transit costs to B. But if A > >>and > >> C have very low levels - does it still makes sense? Does peering costs > >> anything if ISPs are in same exchange? Does at low traffic level it > >>makes > >> more sense to keep on reaching other ISPs via big transit provider? > > > >One thing to consider is that peering can benefit both networks not just > >because of bandwidth savings, but because (given sufficient clue) they > >can deliver better performance and reliability to their mutual customers. > > > > > > > > -- -Matt Chung
Re: VMware Training
Hey Phil, I recently did the VCP certification/course through VMWare however I was working with the technology over the past 5 years. Based off your desire to gain experience with it, my recommendation is to load up VMware Workstation on your computer and deploy ESXi instances as the guests. This is a cost feasible and although performance won't be production grade, you have the ability to play with clusters, DRS/HA config, OpenSAN (for your block based storage), etc. There is a myriad of training docs available but if you do want the certification itself, you'll have to go through the official course(s). Cheers, Matt Chung On Wed, Feb 19, 2014 at 12:14 PM, Phil Gardner wrote: > Not sure if this list is the best place, but it is probably the only list > that I'm on that won't give me a bunch of grief about the chosen technology. > > I looked at VMware's site, and there are a ton of options. I'm wondering > if anyone has some basic suggestions or experiences. > > I'm a Linux admin by trade (RH based), with "ok" networking ability. I'm > sufficiently versed in deploying scripted ESXi (including 5.x) > installations for a specific environment, including vswitches/SAN config > (but only with NFS datastores backed by a NetApp, unfortunately, no > blockbased stores). > > I'd like to get experience deploying VCenter clusters, down to DRS/HA > config, other block based storage, and anything else a large environment > needs. > > Thoughts or experiences? > > -- > _ > Phil Gardner > PGP Key ID 0xFECC890C > OTR Fingerprint 6707E9B8 BD6062D3 5010FE8B 36D614E3 D2F80538 > > -- -Matt Chung
Contributing to the community
I've been so fortunate and appreciative over the years to have colleagues
(many whom I consider my close friends) cultivate my career by providing
sound advise that I will continue to pass on. In addition to those I've
known personally, I have gleaned a substantial amount of information
through many of you who've contributed to these threads, blogs, and so on.
Within the organizations I've worked for, I have always been an advocate
for sharing knowledge in order for the company to grow collectively; I
truly believe its infectious. But I digress...
At my previous company (regional WISP) as a network engineer, I was able to
get buy in from the partners to conduct training for our call center in
effort to better support our customers. By institutionalizing a
methodical approach to troubleshooting (and performing root cause
analysis), we can filter out many potential issues (i.e why check if there
is network connectivity if you are getting an HTTP response - ruled out the
lower stack). That was great however...despite contributing to my
organization, I've always felt that I haven't performed due diligence when
it comes to contributing back to the network/IT community as an entity.
Excuses have been made ("I don't have time") on my part and I realized that
everyone here is a working professional as well. I've never been an active
participant like many of you.
As a person who is passionate about this field (as well as a working
professional), how do you find the time in order to contribute? Do you ever
feel that the post may be redundant? Another factor I've always took into
consideration was the fact that although I may be knowledgeable and
proficient in one facet, someone out there is the true expert (i.e assisted
in developing the RFC) and has a deeper understanding than I do (which I
feel my contribution may be inadequate).
--
-Matt Chung
Re: job screening question
A former manager of mine once told me you can gauge a persons understanding by the questions they ask and I personally agree with this statement. Most of us will be able to make a reasonable assessment of the person by listening to the content of their questions. I'm not looking for an immediate resolution, but trying to understand the thought process of the individual. I feel realistic scenarios provide some insight on the individual's analytical skills. "A client cannot access the website "http://xyz.com";. What do you do to troubleshoot this issue?" Depending on the candidate, I've seen a variety of answers: 1) "Can you ping the device?" 2) "Can you access the gateway?" 3) "What does the running config look like on the router" 4) "Is there a firewall in between" I believe these questions may be asked in the right context provided there is enough information to isolate the issue to the network however the statement is devoid of anything useful that would make the network suspect. I would like to hear some questions such as: "are other websites accessible? Or is the only website the client is experiencing issues with?" "was the website working previously? when did it start happening?" "what does the client see on their screen ? are they getting an error?" These questions reflect the persons ability to accurately understand the problem before deep diving into the technical details. From there, you can get more technical. "Client is receiving an HTTP 404 error." Great, rule out network since this is an application layer response... just my .02. On Fri, Jul 6, 2012 at 8:28 AM, wrote: > I agree. Let the person talk do a few probing questions based off what > they say. If you yourself have any value you should be able to tell if they > have a chance. > > Also I would prefer someone who says I don't know for sure but maybe > something along these lines, and then wants to know the right answer. > Passion is also important, if you are willing to hire someone who is in it > for just a paycheck, save yourself the headache and get a contractor. > -- > Sent from my Android phone with K-9 Mail. Please excuse my brevity. > > Matthew Palmer wrote: > > On Thu, Jul 05, 2012 at 11:04:05PM -0400, Robert E. Seastrom wrote: > > Diogo Montagner writes: > > > For screening questions (for 1st level filtering), IMO, the questions > > > has to be straight to the point, for example: > > > > > > 1) What is the LSA number for an external route in OSPF? > > > > > > This can have two answer: 5 or 7. So, I will accept if the candidate > > > answer 5, 7 or 5 and 7. Later on (the next level of the interview), a > > > techinical interviewer will chech if the candidate understand the > > > differences of LSA 5 and 7. > > > > Frankly, this feels a bit like asking what the 9th byte in an IP > > header is used for (it's TTL, but who's, uh, counting?) -- "That's why > > God gave us packet analyzers" should be counted as an acceptable > > answer. If not, you'll find yourself skipping over plenty of > > extremely well qualified candidates in favor of those who have crammed > > recently for some sort of exam in hopes of compensating for their > > short CV. > > Ugh, I know someone (thankfully no longer a current colleague) who ardently > *defends* his use of questions like "what does the -M option to ps do?" on > the basis that "any senior person who knows what they're doing should know > all the options to ps!". No, you useless tit, anyone who knows what they're > doing should know how to read a bloody manpage. > > Trivia tests get you hiring people who know trivia. Knowing trivia has it's > productivity benefits, but if you can't apply it, it's useless. > > - Matt > > -- > Politics and religion are just like software and hardware. They all suck, > the documentation is provably incorrect, and all the vendors tell lies. > -- Andrew Dalgleish, in the Monastery > > > -- -Matt Chung
Re: LA locally owned ISP
Hey Jeroen, Hope all is well. I use to work as a network engineer at a regional ISP based out in LA - Bel Air Internet. Feel free to unicast me if you have any questions. On Tue, Jan 8, 2013 at 12:43 PM, Jeroen van Aart wrote: > Not exactly a nanog subject but I would like to know if there is a > (ideally) locally owned ISP in LA that's knowledgeable, for DSL service. > Something like cruzio in Santa Cruz. Trying to avoid the big ones such as > AT&T and comcast. > > Thanks, > Jeroen > > -- > Earthquake Magnitude: 4.0 > Date: Tuesday, January 8, 2013 14:46:33 UTC > Location: Southeastern Alaska > Latitude: 56.0080; Longitude: -135.4542 > Depth: 10.00 km > > -- -Matt Chung
Performance Issues - PTR Records
I work for a regional ISP and very recently there has been an influx of calls reporting "slowness" when accessing certain websites (i.e google.com/voice/b) via HTTP. After performing a tcpdump and analyzing the session, I have been able to pinpoint the latency at the application layer. After the tcp session has been established, it takes up to 15-20 seconds before the application begins sending data. The root of the problem was that the PTR record for our customer(s) address does not exist. As soon as the record is created, latency from the application is eliminated. This is analogous to latency when accessing a server over SSH when no PTR is available. A seperate packet capture from another customer exhibiting similar performance behavior showed many TCP retransmissions. At first glance, I assumed this was network related however this correlates with the application not responding and inducing retransmissions at the TCP layer (different symptoms, same problem). Historically, there was no compelling reason to create PTR records for our CPE however more and more applications seem to be dependent on it. Although we will be assigning a record for each address, my question is why is the application (specifically HTTP) dependent on a reverse record ? What is the purpose? Hope this is helpful as well -- -Matt Chung
Re: Performance Issues - PTR Records
We really have no objections to creating records for our IPs however there was no compelling reason previously. With the manifestation of performance issues, we are currently creating a generic record for our addresses. I assumed that the applications would take absent records into consideration instead of waiting and timing out before responding with data. Trying to troubleshoot this issue from the limited visibility is difficult ; the latency the application is introducing is abstracted (unless I am unaware of that troubleshooting technique). Sent from my iPhone On Nov 2, 2011, at 5:58 PM, J wrote: > PC wrote: >> What happens if the ISP never defines a name server with their RIR for >> their provider-independent address space? Does ARIN point to somewhere >> which supplies NXDOMAIN? Just a thought -- I don't have a clue. >> >> It is entirely possible they have it pointed to their non-existent or >> broken DNS. Given current best practices, I see no reason not to assign a >> generic x.x.x.x-dynamic.customer.isp.com DNS across their netblock. > > I think that returns SERVFAIL somewhere down the line? > > Does it make sense to reinforce the behaviour (good and bad terms left for > another time), while looking forward to v6? >
