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SG300 DHCP Relay with OS X

We recently switched to an SG300-52 for our network from an older Dell PowerConnect switch.  Everything seemed fine during testing so obviously this was phased in and has now taken over the DHCP relay tasks from the Dell switch.  To make a long story short, everything appears to be configured correctly, but for whatever reason DHCP requests from OS X clients are not being handled correctly.

I've used Wireshark to monitor the traffic on both sides of the switch (across VLANs) -- Windows clients broadcast a DHCP discovery, which the switch repeats to the DHCP server (Windows Server 2003 R2).  The server responds with an offer, which the switch naturally broadcasts back to the original client's VLAN, and the DHCP lease process completes normally.  With an OS X client however, the server's offer is never passed along by the switch, so it never receives an offer to act upon.  The result is that Windows clients operate perfectly, while OS X clients are left to resort to an auto-assigned address and obviously lose network connectivity.  I was unable to find any combination of options to permit this to work beyond allowing the older PowerConnect switch to handle DHCP relaying again.  This has been observed with four different OS X systems, so I don't believe it's isolated to a simple setting on them, however we are primarily a Microsoft office so I could be mistaken.

Is this a known issue with the switch firmware or has anyone else experienced it and know of a potential workaround?  The switch is running and there were no known communication issues beyond DHCP.


SG300 DHCP Relay with OS X

Hi Damon, I have no idea why it wouldn't work. But a possible work around is to let the switch be the DHCP server for your network or a specific vlan.

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-Tom Please mark answered for helpful posts
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SG300 DHCP Relay with OS X

Since I'm messing with DHCP relay, and I have a mac, I unplugged one of the (working) windows machines and plugged in my mac and reproduced the issue.

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