05-29-2012 07:25 PM
I've enabled jumbo frames in Networking -> LAN (Local Network) -> Jumbo Frames on an RV180W running the base firmware (1.0.0.30).
The switch seems to pass jumbo frames just fine (like ... almost every switch these days), but the router itself silently drops jumbo frames.
Is this a known bug?
This makes enabling jumbo frames on clients impossible, since it will break some external connectivity. (I.E. when two endpoints are on networks with jumbo frames, they will then negotiate a high MTU over the WAN, but the router will silently drop large frames and they won't get an ICMP Fragmentation Needed, etc. because the router simply drops large frames).
05-30-2012 12:18 AM
Personally I dont think it is a known bug, more than your RV180 maybe filtering packets in one of the settings in the router.
the review on smallnetbuilder showed it supported upto 9000 frames.
Regards Simon
05-30-2012 08:39 AM
Simon Slater wrote:
the review on smallnetbuilder showed it supported upto 9000 frames.
That's only between LAN devices -- not to the router itself.
If the router itself doesn't support jumbo frames, it breaks end-to-end connectivity to other endpoints (outside of the WAN) using jumbo frames internally.
05-30-2012 12:28 PM
I can see why jumbo frames would be supported across the wan. After all this router is mainly for use as a Wan interface to the internet. Most adsl and fibre modems only support an mtu of 1500. The internet will only support that also so what you are expecting is beyond the design of the router
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05-30-2012 12:31 PM
Correct, but that's not the issue.
The issue is that clients have to negotiate their own MTUs.
I'll post a more detailed summary later. This is a well known problem with enabling jumbo frames on networks.
05-30-2012 12:34 PM
Have you raised a Ticket with Cisco?
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05-30-2012 04:36 PM
I haven't. Is there a way to do that online/via e-mail?
05-30-2012 11:37 PM
Try here: http://www.cisco.com/en/US/support/tsd_cisco_worldwide_contacts.html
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