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Broadcast large UDP datagrams between VLANs


I wish to broadcast large UDP packets between two VLANs (on the one set of stacked 3750 switches).
I have setup an ip helper which allows me to broadcast between vlans. That works fine, but I am limited to datagrams around 5912 bytes in size.
I want to be able to broadcast larger datagrams.
I can successfully broadcast larger datagrams (65000-ish bytes) within the one vlan, but not between two vlans.
Am I able to increase the size of broadcast UDP datagrams between vlans and if so, how?
Thanks in advance.
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Hmm, I'm wondering whether a helper cannot forward fragments.

If not, if you enable jumbo support on the 3750, you might be able to send larger diagrams, but perhaps not larger than MTU.

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Thanks Joseph,Wireshark

Thanks Joseph,

Wireshark informs me that datagrams less than around 5912 bytes are fragmented and reassembled between VLANs successfully by the helper.

Jumbo frames are enabled on the 3750's with an MTU of 1500.  I'll up this to 9000 to see if it makes a difference.




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