[c-nsp] Very slow page load / DNS response on Cisco 1841

Scott Granados scott at granados-llc.net
Thu Sep 15 12:27:47 EDT 2011


Hi, I’ve been googling and finding a lot of matches but none of them seem to have a definite solution or at least none that have worked so far.  Wonder what I’ve missed or if anyone has some good ideas.

Here’s the background.  I have a Cisco 1841 router with 2 fast E interfaces configured, one as inside and one as outside facing a cable delivered service with an ethernet port on a terminal adapter and fixed (static) IP range.  When using another brand of router I get pretty good performance and no lag when oping pages or using applications over the public Internet.  Nat is configured in a pretty standard way as follows.

int fast 0/1
desc outside access
ip address a.b.c.d/29
ip nat outside


int fast 0/0
desc internal interface
ip address 192.168.1.0/24
ip nat inside of course is slower.  If I do a name resolution by hand using dig or nslookup the result seems to return pretty quickly although being a human what seems fast to me may not really be.  I have added a forward on UDP 53 to the internal name server as suggested in one post but no improvement.  I’ve also insured proxy arp is disabled.  Anything I’ve missed?  This is a regular 1841 so there’s no inspect commands I don’t believe even though I’ve seen that referenced in another post I believe that’s PIX related.

Any ideas, I’m fairly stumped and googling isn’t yielding much in the way of stuff I haven’t tried.  Keep in mind other brands of gear work correctly so it has to be something I’m missing, I think.

Thanks
Scott




access-list 1 192.168.1.0 0.0.0.255

ip nat inside source list 1 interface fast 0/1 overload


ip route 0.0.0.0 0.0.0.0 a.b.c.f/29  (outside gateway on fast 0/1’s attached terminal adapter)


When I use this config and attach a device to the inside network, using an internal windows server running DNS / DHCP and the general package of supporting protocols I get a huge delay from sending the web request with the browser to the page downloading.  I’ve done the tests suggested which show when using an IP in stead of name the page seems to load faster although any referenced code inside the page that uses DNS


More information about the cisco-nsp mailing list