This is a question which is probably a little off topic, and probably not relevant to the question, but I've been wondering about it for a while (minutes anyway). We had a similar problem although fairly localised that certain users within a network could not access certain web servers. Turned out to be the 'Do not Fragment' bit set on the server, and the traffic was being passed over a Triple DES link which pushed the packet size over the default MTU of 1500. I changed the encapsulation to PPP and upped the MTU to get over it. These same users are accessing the internet over the same link, with no problems, so I take it that setting the 'Do not Fragment' bit is not a regular thing? So after all that prattle, the question is: What is the reason for setting the 'Do not Fragment' bit? I remember reading somewhere that later versions of IOS have a setting which basically ignores this bit, but why set it on the server if it is OK to ignore it. Cheers, Gaz ""Chuck Larrieu"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > In answer to this puzzle, the consensus on NANOG was that the problem may be > related to an MTU mismatch. > > A couple of folks keyed in on "DSL" and the described symptom, and noted > that there have been similar problems caused by MTU issues within the DSLAMS > used by the carriers noted in the message below. > > As of this writing, the guy who asked the question has not reported any > further information. > > Chuck > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of > Chuck Larrieu > Sent: Friday, September 07, 2001 7:40 PM > To: [EMAIL PROTECTED] > Subject: FW: web pages not loading (from certain networks) but not a > [7:19074] > > > Saw this one on NANOG today. Any of you troubleshooting gurus want to take a > crack? > > ( BTW, I believe I saw this problem myself today. OTOH, my issue could have > been related to that stupid proxy my employer now makes me use. ;-> ) > > I'll post the answer the NANOG folks suggested later this weekend. > > Chuck > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of > Nanog > Sent: Friday, September 07, 2001 7:52 AM > To: [EMAIL PROTECTED] > Subject: web pages not loading (from certain networks) but not a routing > issue. > > > > Ok guys, > > Interesting problem that seems to have started on Friday. > > Here's the deal, it seems that certain (not all) web pages on various sites > we host are not loading for certain customers. It started on Friday with > visitors on Verizon DSL waiting forever for pages to load. > > Yesterday and today PacBell DSL and some Netcom customers started > complaining. > > This only seems to occur on HTTP traffic. If we have the visitors try HTTPS > the pages load fine (with the normal encryption slowdown). > > We've looked at Layers 1-4, and can't see any problems, ping looks great, > interfaces and cpus on routers, servers and switches look fine. > > It's almost like it's a transparent cache "bug". Anyone know if Inktomi, or > any major cache vendors rolled out any new code this week? > > For that matter does anyone know what caches Verizon and SBC use for > starters? > > Other variables: it only seems to occur on IIS based systems (I know I know, > no flame wars or suggestions for replacements). Although it's not happening > on all of our IIS servers. > > Any clues are greatly appreciated. > > Steve Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=19247&t=19247 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
