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iLO 4 will not talk to switch only to a computer

Occasional Contributor

iLO 4 will not talk to switch only to a computer

Hi gents,


I have a lovely rack of brand new DLs (7 360ps and 2 380ps) all with iLO Advanced licensing and configured with Static IPs. All of the iLOs are connected to access ports on a Cisco Catalyst 3560v2 switch. All 9 ports come up (for those familiar with Cisco switch reports all ports as up, line protocol up) without issues however one of the servers absolutley refuses to talk to the switch. We have tried the following options:


  • Replaced network cable (tried 3 different ones but all straight through no crossovers).
  • Enabled portfast on the switch port.
  • Different switch port (same port works with other servers).
  • Different switch entirely.
  • Force port setting on iLO and switch to 100 Full Duplex.
  • Factory reset iLO.
  • Update iLO firmware (the other 8 servers are now running iLO 4 1.10 without issues where as the faulty machine is running iLO 4 1.20).

Using Cisco port SPAN we confirmed there is NO traffic entering the port from the server.


On the other hand if a computer is assigned static IP in the same subnet and connected directly to iLO via straight through cable the connection works perfectly.


After some aditional testing we determined that the iLO on this particular server will not communicate with network unless it autonegotiates 1 Gbps link speed. If the far end is not capable of 1 Gbps speed the connection will not work and since our switch is 10/100 Mbps only this is the cuase of the issue. Forcing 100 Mbps Full Duplex in iLO configuration prevents all access to the interface, even if connected directly to a device cofigured the same way.


Any suggestions? Is the iLO simply faulty and I should get HP to replace the motherboard?



P.S. This thread has been moved from Servers > General to ProLiant Servers (ML,DL,SL) - HP Forums moderator

Oscar A. Perez
Honored Contributor

Re: iLO 4 will not talk to switch only to a computer

Are you connecting the iLO dedicated NIC to your switch or you are using the server's shared NIC?


Autonegotiation is always the best option for iLO. Forcing Full duplex on one side can cause interoperability problems.

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Occasional Contributor

Re: iLO 4 will not talk to switch only to a computer

No we use the dedicated iLO NIC. The shared port is supposed to be unable to provide Remote Console functionaltiy (except textual) and that is the main reason why we got iLO in the first place.


We were forcing specific speed / mode on the interface for testing only. We left it in Auto mode and it still does not work. We tested it against two laptops which have 1 Gbps capacity and it worked fine. On the other hand we also tested it against a laptop with 100 Mbps port, a USB based 100 Mbps Ethernet adapter and two switches (both are 3560s) and in all four cases while the link is reported as negotiated correctly (either by Windows or by the switch) we cannot communicate with the iLO at all.


Obviously there is some failure of the iLO hardware - I'll be giving HP a call and hopefully it wont take too long to convince them to replace the motherboard...

Frequent Advisor

Re: iLO 4 will not talk to switch only to a computer

Can you ping the iLo 4 1.20 machines from the switch?


We do a lot of diags in the factory through iLo.


Don't be a turd.