We have a Sonicwall firewall that that has the LAN port connecting to one of our core switches (ProCurve 5304XL).
On the Sonicwall, the LAN Link Speed is: Auto Negotiate
On the ProCurve Switch, the port that the Sonicwall connects to is set to: Auto
I know that sometimes the negotiation does not work correctly, so I wanted to know -- how can I tell if I'm having a duplex issue between these two connections.
Please see the image below for my reasoning to be suspicious of a duplex issue.
Step 1: You see two different SAN (NetApp) NICs (LACP) each at about 15Mbps & 34Mbps.
Step 2: Trk5 & Trk6 are LACP groups for the SAN: "trunk A5,C12 Trk5 LACP
" at 15Mbps & 33 Mbps
Step 3: Trk1 on 1st core switch (LACP group that communicates with the 2nd core switch)
Step 4: Trk1 on 2nd core switch (LACP group that communicates with the 1st core switch)
Step 5: All of a sudden a bottle-neck. Traffic is forwarded to the B4 port on i1whl-mdf-c02 switch (2nd core switch). B4 is the port that connects to our firewall.
Step 6: Traffic is forwarded from B4 to LAN port of Sonicwall.