Steelhead Appliance

[cgeary]

Glad I could help :)

[johno1066]

Of course, that's why i'm not seeing collisions, (smacks head), thanks Chris

[cgeary · Accepted solution]

This depends on which device has been hardcoded and which has failed auto negotiation. In this case, the Steelhead was hardcoded to 100/FULL. By definition it cannot experience collisions because it believes it is transmitting and receiving in full duplex. You'll only see rx errors here. The switch, however, being at auto will have failed to negotiate and dropped to carrier speed and half duplex. Carrier speed is always detected so in this case 100/Half. The switch may have recorded collisions as well as errors.

[johno1066]

Thanks Chris,

Very interesting and highlights the importance of tests on deployment. May I ask if  rx errors on the lan0_0 specific to duplex issues or there any other contributory factors or checks that I can perform? the reason I ask is that I would have expected to see collisions if there was a duplex mismatch but in this case there are none at all.

Cheers

[cgeary]

If the wan router is hard coded to 100/Full, then you are forced to use the same configuration on all three other interfaces. The reason for this is to handle the situation where the Steelhead goes in to hardware bypass, you need to cater for that time when the cables are joined. It is also critical when using hard coding that the cable types are correct as auto-mdix is also disabled.

The potential problem with hardcoding to the wan port speed is that (depending on your WAN bandwidth and SH model), you could find that 100mbps on the LAN side isn't high enough.

Your choices here are:

1. Accept that fact and be content that in a bypass scenario your network will not blackhole

2. Choose to set the lan switch and lan0_0 ports to auto negotiate to gain the benefit of gigabit speeds but risk blackholing in a bypass scenario.

[johno1066]

G'day,

i'm receiving an rx count error count that matches exactly, the number of counted frames, the steelhead is giving a duplex alarm however there are no collisions. The switch (lanside) is auto negotiate, (100 full) and gig capable, the steelhead  Lan0_0 & wan0_0 are both  hardcoded to 100 full in order to match the WAN interface which is 100Mb capable. I understand from other threads that with gigainterfaces it is preferable to have auto negotiate but that to do so would likely leave us with a speed mismatch between lan and wan interfaces. Cheers