try turning off autonegotiate (at both switch and router). that seemed
to do the trick for us.
Jim Warner wrote:
>
> We are getting ratty performance on a new Gig-E point-to-point link
> between our 7507 and Catalyst 5500.
>
> Prior to bringing up the Gig-E link, the connection between these devices
> was fast ethernet. Now, with OSPF set to prefer GE, it looks like:
>
> 7507 Cat5500
>
> ------------ ---------------
> | VIP4-80, | Fast-E |WS-X5213A |
> | slot 0 |-----------------|port 5/2 |
> | | | |
> | Gig-E | LX Gig-E |WS-X5403 |
> | slot 1 |-----------------|port 3/1 |
> | | | |
> | | |Route-Switch |
> | RSP 4 | |Mod slot 4 |
> | | | |
> ------------ ---------------
>
> We have rigged some static routes so we can perform four different
> ping tests: (out Gig in FE, out Gig in Gig, out FE in FE, out FE in Gig)
>
> Ping tests that take the Gig-E path from the 5500 --> 7500 are
> slow and have a high round trip variance. Response times on
> the other paths are sub millisecond. From IOS perspective:
>
> Gig-E
> Success rate is 100 percent (3341/3341), round-trip min/avg/max = 1/25/260 ms
>
> Fast-E
> Success rate is 100 percent (1000/1000), round-trip min/avg/max = 1/1/12 ms
>
> The behavior holds with delay probes through the routers (to/from unix
> computers) where the probe packets are not process switched. In all
> cases, we are not seeing packet loss, only delay. The amount of delay
> appears to correlate with the average traffic through the routers -- 25
> mS of "extra" delay corresponds to about 10 Mb/s and 2500 packets/s.
>
> To see the effect of switching from FE to GE this morning, see:
>
> http://noc.ucsc.edu/rt-delay.gif
>
> We are puzzled. None of the error counters we normally look at are
> incrementing. Flow control is off everywhere. Duplex is full everywhere.
> I guess I'm looking for suggestions of really-dumb-things-I-forgot-to-check.
>
> Thanks in advance... -jim warner, UCSC
This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:12:36 EDT
