Major Problem with DHCP setting MTU Correctly.

[zpro]

First: sudo lspci -vv <snip it>
 02:00.0 Ethernet controller: Marvell Technology Group Ltd. 88E8036 PCI-E Fast Ethernet Controller (rev 10)
         Subsystem: Gateway 2000 Unknown device 0506
         Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
         Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
         Latency: 0, Cache Line Size: 32 bytes
         Interrupt: pin A routed to IRQ 58
         Region 0: Memory at c0100000 (64-bit, non-prefetchable) [size=16K]
         Region 2: I/O ports at a000 [size=256]
         Capabilities: [48] Power Management version 2
                 Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=0mA PME(D0+,D1+,D2+,D3hot+,D3cold+)
                 Status: D0 PME-Enable- DSel=0 DScale=1 PME-
         Capabilities: [50] Vital Product Data
         Capabilities: [5c] Message Signalled Interrupts: 64bit+ Queue=0/1 Enable+
                 Address: 00000000fee00000 Data: 403a
         Capabilities: [e0] Express Legacy Endpoint IRQ 0
                 Device: Supported: MaxPayload 128 bytes, PhantFunc 0, ExtTag-
                 Device: Latency L0s unlimited, L1 unlimited
                 Device: AtnBtn- AtnInd- PwrInd-
                 Device: Errors: Correctable- Non-Fatal- Fatal- Unsupported-
                 Device: RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop-
                 Device: MaxPayload 128 bytes, MaxReadReq 512 bytes
                 Link: Supported Speed 2.5Gb/s, Width x1, ASPM L0s, Port 3
                 Link: Latency L0s <256ns, L1 unlimited
                 Link: ASPM Disabled RCB 128 bytes CommClk- ExtSynch-
 -----------

 THAT is the built-in ethernet 10/100 for my Gateway laptop.
 (running edgy 6.10 live cd 10-11-2006 ) with updates.

 ----
 Next LOOK at the MTU's of eth1 (which is the 10/100 to the my cable modem )
 rick@KB32bit:~$ sudo ip link list
 1: lo: <LOOPBACK,UP,10000> mtu 16436 qdisc noqueue
     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
 2: eth1: <BROADCAST,MULTICAST,UP,10000> mtu 576 qdisc pfifo_fast qlen 1000
     link/ether 00:03:25:28:93:b3 brd ff:ff:ff:ff:ff:ff
 3: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop qlen 1000
     link/ether 00:14:a5:41:e4:99 brd ff:ff:ff:ff:ff:ff
 4: sit0: <NOARP> mtu 1480 qdisc noop
     link/sit 0.0.0.0 brd 0.0.0.0
 rick@KB32bit:~$
 ----------
 See how its set to "576" AND NOT "1500", this would explain allot of very slow
 downloads.. and stalling.
 ----------
 Now if I do this:

 rick@KB32bit:~$ sudo ifconfig eth1 mtu 1500
 rick@KB32bit:~$ ip link list
 1: lo: <LOOPBACK,UP,10000> mtu 16436 qdisc noqueue
     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
 2: eth1: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qdisc pfifo_fast qlen 1000
     link/ether 00:03:25:28:93:b3 brd ff:ff:ff:ff:ff:ff
 3: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop qlen 1000
     link/ether 00:14:a5:41:e4:99 brd ff:ff:ff:ff:ff:ff
 4: sit0: <NOARP> mtu 1480 qdisc noop
     link/sit 0.0.0.0 brd 0.0.0.0
 rick@KB32bit:~$
 ----------------

 You can see its NOW that I've set the MTU's to 1500
 and my download speeds have increase allot very much so.
 --------------

 BUT WHEN, I reboot, my laptop and do this:
 rick@KB32bit:~$ sudo ip link list
 1: lo: <LOOPBACK,UP,10000> mtu 16436 qdisc noqueue
     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
 2: eth1: <BROADCAST,MULTICAST,UP,10000> mtu 576 qdisc pfifo_fast qlen 1000
     link/ether 00:03:25:28:93:b3 brd ff:ff:ff:ff:ff:ff
 3: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop qlen 1000
     link/ether 00:14:a5:41:e4:99 brd ff:ff:ff:ff:ff:ff
 4: sit0: <NOARP> mtu 1480 qdisc noop
     link/sit 0.0.0.0 brd 0.0.0.0
 rick@KB32bit:~$
 -------------------
 As you can see the MTU's are Back to "576" and not setting at "1500"

 SO, THERE IS a bug with DHCP or your ethernet driver somewhere....???

 Hope this is enough information to FIX it,
 if not please email me. <email address hidden>

 Thank You.

[Jarmo Ilonen (trewas)]

Probably the same issue as bug #61989. If it is, removing "interface-mtu" from request-line in /etc/dhcp3/dhclient.conf and rebooting will fix it.