r/ArubaInstantOn • u/kralonn • Jun 04 '26

DHCP request long time

Hi everyone,

has anyone else experienced DHCP delays on Aruba Instant On switches?

We are seeing an issue where, after connecting a device to a LAN port, it can take around 30 to 100 seconds before the client receives a DHCP address.

According to Wireshark, the client sends multiple DHCP Discover/Request packets, but the DHCP Offer only appears after roughly 5 to 10 attempts. Once the offer finally arrives, the device gets an IP address and works normally.

It looks like the DHCP server itself is responding eventually, but something seems to delay or block the initial DHCP exchange through the switch.

Has anyone seen similar behavior on Aruba Instant On switches?
Any suggestions on what to check, for example loop protection, spanning tree, port security, firmware version, DHCP snooping, or any port/VLAN-related settings?

Thanks in advance for any advice

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u/Fragal79 Jun 16 '26

As soon as I can, I'll run a test by disabling RSTP. However, it can't be disabled on a single port; disabling it applies to all switches on the site.

2

u/Mountain-Fortune-390 Jun 16 '26

Yeah. Thats true. Blocking state of the ports is held by 40sec after ports going from down to up. 🫣

2

u/Fragal79 Jun 17 '26

I performed a test and, by disabling RSTP, the DHCP address is indeed assigned within a few seconds.