Alas, those sys admins. I love your way of putting it. (They know how to right click things but not much more. ;-) The thing that gets me is that they are sure that they know networking.
Thanks for a helpful story. Priscilla John Brandis wrote: > > I would like to tell you about a problem I had in relation to > this. > > In November last year, I rolled out a new building for my > current employer. > We are not a huge company, but it was around 600 ports using > 100% Cisco > gear. The challenge was, that on thursday night, I took > delivery of the > gear. Friday it had to be in the new building and working, as > with all the > servers, routers, firewall and etc (did I mention that we did > an IP change > that same night across the WAN) > > Any way, the sys admins, gave me 6 machines that were used here > in our > company to test with. I configured the ports, as 100MB full, no > auto as some > machines had problems with this. So with all 600 floor ports > configured, > machines were taken out of the box's and turned on. Only about > 200 of the > 600 machines got a network link up. I could not understand > this. I spent > around 40 minutes looking at the switch configs looking for > error's. Just > saw non active ports. By this time, the Regional manager was > yelling and > screaming. I told him to hang on, as I will get this sorted out > soon (the > sys admins were encouraging this guy as we dont get along, they > dont know > much outside of right clicking objects).. > > I played with the port settings on a handful of ports, set them > back to > auto, set others to 10mb. This was proving to work. The problem > was, that > the ghost image created by the sys admins, was not such a > standard at all. > In total, there were around 5 images in use out on the floor. > All created > back in the days when this company was using hubs. On some of > the PC's, the > network settings of the NIC, was set to 10mb/s, others were set > to 100mb/s > half dup...It was a nightmare. > > In the end, I got the network running fine, however I did look > stupid for a > period of time. WHilst I was getting the network running, the > sys admins > took the regional manager to breakfast to calm him down. They > had a good > chat about why this was my fault...Now days, those sys admins, > only have > 512kb/s access to the rest of the network as opposed to Gig E. > > Summary, get better sys admins. Sys admins must start to > understand that > there ghost images and your network need to work together. Hope > this helps > some of you. It has made me a better technician. > > John > Sydney Australia > > > -----Original Message----- > From: John Neiberger [mailto:[EMAIL PROTECTED] > Sent: Thursday, 29 May 2003 2:43 AM > To: [EMAIL PROTECTED] > Subject: Re: port/duplex configs [7:69582] > > > I don't have enough time at the moment to explain this as well > as I should. > Do a quick search on autonegotiation in the archives and I have > some recent > postings that explain it better. here's the short version: > > The only connection method specific in the FastEthernet > standard is AUTO. > If you do anything other than AUTO you are out of spec and the > behavior is > not consistent. When you manually set your speed and duplex > settings some > devices disable autonegotiation (NWAY) entirely. Others still > participate > in NWAY but they only offer the configured settings. The > problems occur > when you connect two devices that use different methods. If > you do, you're > guaranteed to get a duplex mismatch. > > The side that completely disables NWAY will stick to your > manual settings, > 100/Full, for example. The other side, if it still > participates in NWAY, > will still expect an NWAY-capable device to be attached. Since > it doesn't > detect NWAY, it falls back to half duplex, and there's your > mismatch. > > Cisco's newer switches--like the 6500s and 2950s--disable NWAY > entirely if > you manually set the speed and duplex. About 98% of the NICs > in our > environment use the other method, which almost guarantees > failure if we > don't use AUTO. If you're going to manually set your settings > with newer > switches, 100/Full is the absolute worst possible setting. If > you want high > speed with manual settings the best setting is 100/Half. That > way, if > connect two devices that behave differently, you'll still be > okay when the > NWAY-capable NIC falls back to half duplex. > > Cisco's older switches, like the 2900XL series, still > participated in NWAY > even if you used manual settings. So, if you have a 2924XL > with manual > settings that needs to be replaced and you replace it with a > 2950-24 with > the identical config, I wish you luck for you are about to > learn all of this > the same way I did. I used to be a radical anti-auto person > until I got our > 6513, 2948Gs, 2980Gs, and a bunch of 2950s. I've since changed > my mind and > I'm now a very pro-AUTO person. > > The real killer here is that most NICs will continue to report > their manual > settings regardless of their operational settings. If you > manually set a PC > NIC to 100/Full, many times it will continue to report full > duplex even if > it has fallen back to using half duplex. > > Perhaps later today I'll have more time and I can get into some > more > details. > > Regards, > John > > >>> Troy Leliard 5/28/03 4:52:30 AM >>> > I have seen this too, and like Ian I would normally go with > 100/Full > manually configured on botht he Cat and the end device > (obviously assuming > both devices support this settings). In real life, I have > often found that > setting the cat to Auto will often lead to duplex / speed > mismatches > (especially with Sun kit) The only time I have made use of > Auto is when I > am not 100% sure if the end device support 100MB, some of our > legacy > printers are 10MB half duplex, and indeed a number of the > 2511's are only > 10MB too.] > > ian williams wrote: > > > > This has come up in the ccie written. > > If I understand this subject correctly AUTO , sends out > packets > > to try and > > match the 2 devices up with regards to speed and duplex. > > If your getting connection problems this would be a speed > > issue. If its some > > sort of packet loss/error then this could be a duplex problem. > > I have always configured the CAT port manually so there isnt > > any problems. > > > > Why would you choice AUTO? > > > > > > > > ----- Original Message ----- > > From: "John Neiberger" > > To: > > Sent: Tuesday, May 27, 2003 5:35 PM > > Subject: Re: port/duplex configs [7:69582] > > > > > > > >>>> ian williams 5/27/03 10:29:21 AM >>> > > > >I have always configured ports on CAT switch to 100/full > > manually instead > > > of > > > >AUTO. > > > >What is recommended when asked this question for the CCIE > > written. Should > > > >both the end > > > >device ( NIC ) and switch both be configured to 100/FULL? > > > > > > I can't imagine why such a question would be asked on any > > exam since the > > > correct answer is that you configure whatever is necessary > to > > establish a > > > connection with the end device. In my opinion, you should > > always use AUTO > > > unless this causes problems, in which case you hard-set your > > devices to > > > 100/HALF, not 100/FULL. If you'd like the rationale for > that > > I refer you > > to > > > the archives for my previous rantings on this subject. > > > > > > I'd fall over in shock if you were to be asked a question > > like this on > > your > > > exam, but as long as you understand the issues involved you > > should be > > > adequately prepared for whatever question of this type that > > they throw at > > > you. > > > > > > Regards, > > > John > ********************************************************************** > > This email message (and attachments) may contain information > that is confidential to Solution 6. If you are not the intended > recipient you cannot use, distribute or copy the message or > attachments. In such a case, please notify the sender by > return email immediately and erase all copies of the message > and attachments. 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