Firefox/DNS problem, possibly due to two ADSL lines, advice needed
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From: tinnews on 4 Dec 2009 08:21 I have a small SoHo network running (mostly) Ubuntu 9.04 and 9.10 Linux systems. We have two phone lines with ADSL on both from different ISPs. The network is connected to the Internet by a Draytek Vigor 2820n ADSL router which uses one of the ADSL connections and the 2nd WAN port of the 2820n goes via a BT Business Hub (2Wire router) to the other ADSL. This basically works very well, the ADSL connections are shared by the 2820n router on a round robin basis and seem to be used fairly evenly. Since it's not a bonded service some things have to be explicitly routed through either one or the other ADSL connection (SMTP, https and a couple of others), this is done in the 2820n configuration. However I occasionally have a problem when web browsing using Firefox (happened with 3.0.x and now with 3.5.x). Most of the time and with most web sites it works absolutely normally but just sometimes, most often with Google but I have noticed with other sites (Which? and Ebay among others) it simply hangs saying "Waiting for www.google.com" in the status bar. If you leave it what usually happens is that it times out. If you hit the Firefox Stop button and then the Reload button it will always, sometimes after a few repeats of Stop and Reload, successfully load the page it was hanging on. It's as if Google (and other sites that occasionally hang) have some sort of memory of the IP address for the 'session' and when it changes (because I'm connecting via the other ADSL) they refuse to work. This is the reason for forcing https to go via only one ADSL as, for security, bank sites for example *do* check the connecting IP. However I can't really see any good reason for Google to do this and I can't really force http to go through one ADSL as that would rather defeat the object of having two connections. Can anyone suggest whether my diagnosis is right and/or any way to overcome the problem, and/or any other possible diagnosis? -- Chris Green
From: alexd on 4 Dec 2009 10:11 Meanwhile, at the uk.comp.os.linux Job Justification Hearings, tinnews(a)isbd.co.uk chose the tried and tested strategy of: > It's as if Google (and other sites that occasionally hang) have some > sort of memory of the IP address for the 'session' and when it changes > (because I'm connecting via the other ADSL) they refuse to work. This > is the reason for forcing https to go via only one ADSL as, for > security, bank sites for example *do* check the connecting IP. > However I can't really see any good reason for Google to do this and I > can't really force http to go through one ADSL as that would rather > defeat the object of having two connections. > > Can anyone suggest whether my diagnosis is right and/or any way to > overcome the problem, and/or any other possible diagnosis? Force HTTP out of one line and see if the problem goes away. Some load balancing kit has an option to make clients 'sticky' for what WAN interface their traffic is sent out for exactly this reason. Obviously if you don't have many client machines then this has the effect of canceling out the load balancing. -- <http://ale.cx/> (AIM:troffasky) (UnSoEsNpEaTm(a)ale.cx) 15:04:00 up 48 days, 46 min, 5 users, load average: 0.75, 0.56, 0.30 Plant food is a made up drug
From: tinnews on 4 Dec 2009 10:20 alexd <troffasky(a)hotmail.com> wrote: > Meanwhile, at the uk.comp.os.linux Job Justification Hearings, > tinnews(a)isbd.co.uk chose the tried and tested strategy of: > > > It's as if Google (and other sites that occasionally hang) have some > > sort of memory of the IP address for the 'session' and when it changes > > (because I'm connecting via the other ADSL) they refuse to work. This > > is the reason for forcing https to go via only one ADSL as, for > > security, bank sites for example *do* check the connecting IP. > > However I can't really see any good reason for Google to do this and I > > can't really force http to go through one ADSL as that would rather > > defeat the object of having two connections. > > > > Can anyone suggest whether my diagnosis is right and/or any way to > > overcome the problem, and/or any other possible diagnosis? > > Force HTTP out of one line and see if the problem goes away. Some load > balancing kit has an option to make clients 'sticky' for what WAN interface > their traffic is sent out for exactly this reason. Obviously if you don't > have many client machines then this has the effect of canceling out the load > balancing. > Yes, OK, I can try that. I do have the option of making the clients 'sticky' as you say - already done for https. However, as you say also, that rather spoils the load balancing as there are only ever at the most two client machines running at a time. -- Chris Green
From: C. on 4 Dec 2009 18:36 On 4 Dec, 13:21, tinn...(a)isbd.co.uk wrote: > I have a small SoHo network running (mostly) Ubuntu 9.04 and 9.10 Linux > systems. We have two phone lines with ADSL on both from different ISPs.. > > The network is connected to the Internet by a Draytek Vigor 2820n ADSL > router which uses one of the ADSL connections and the 2nd WAN port of > the 2820n goes via a BT Business Hub (2Wire router) to the other ADSL. > > This basically works very well, the ADSL connections are shared by the > 2820n router on a round robin basis and seem to be used fairly evenly. > Since it's not a bonded service some things have to be explicitly > routed through either one or the other ADSL connection (SMTP, https > and a couple of others), this is done in the 2820n configuration. > > However I occasionally have a problem when web browsing using Firefox > (happened with 3.0.x and now with 3.5.x). Most of the time and with > most web sites it works absolutely normally but just sometimes, most > often with Google but I have noticed with other sites (Which? and Ebay > among others) it simply hangs saying "Waiting forwww.google.com" in > the status bar. If you leave it what usually happens is that it times > out. If you hit the Firefox Stop button and then the Reload button it > will always, sometimes after a few repeats of Stop and Reload, > successfully load the page it was hanging on. > > It's as if Google (and other sites that occasionally hang) have some > sort of memory of the IP address for the 'session' and when it changes > (because I'm connecting via the other ADSL) they refuse to work. This > is the reason for forcing https to go via only one ADSL as, for > security, bank sites for example *do* check the connecting IP. > However I can't really see any good reason for Google to do this and I > can't really force http to go through one ADSL as that would rather > defeat the object of having two connections. > > Can anyone suggest whether my diagnosis is right and/or any way to > overcome the problem, and/or any other possible diagnosis? > > -- > Chris Green I would do a bit more experimenting before assuming its due to a connection going down a different route - a lot of larger service providers (e.g. AOL) use load-balanced proxies - so its quite a normal event to see the client address changing half-way through a session. Top of my list of things to look at would be DNS - for a setup like this, I would plan on running my own caching DNS server (e.g. http://homepage.ntlworld.com/colin.mckinnon/colin/) rather than messing around ensuring that DNS requests from a particular providers server are routed through the right connection (alternatively - Google are now in the free DNS business). C.
From: Owen Rees on 4 Dec 2009 20:03
On Fri, 4 Dec 2009 13:21:29 +0000, tinnews(a)isbd.co.uk wrote in <pvenu6-4ur.ln1(a)chris.isbd.net>: >I have a small SoHo network running (mostly) Ubuntu 9.04 and 9.10 Linux >systems. Is there any correlation between the problem and the OS on the system running the browser? Ubuntu 9.10 included some changes that can cause problems if your network does not support IPv6 properly, and especially if your DNS silently discards AAAA requests (as the DNS proxy in my ADSL modem/router does). -- Owen Rees [one of] my preferred email address[es] and more stuff can be found at <http://www.users.waitrose.com/~owenrees/index.html> |