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* UDP MSS
       [not found] <AANLkTi=qOQ0Rmyp78NEE9qSGOTFvgTDFSbDEDCtzoQ04@mail.gmail.com>
@ 2010-12-14  3:47 ` ratheesh k
  2010-12-14  4:00 ` Jan Engelhardt
  1 sibling, 0 replies; 10+ messages in thread
From: ratheesh k @ 2010-12-14  3:47 UTC (permalink / raw)
  To: Netfilter mailing list

In udp , there is no mss discovey.So , if we  set DF bit in IP packet
  and suppose an intermediate router does have disabled icmp-reply
(thru iptables )  and  have less MTU than the sender.

Then , router  will drop the packet ,How client know to fragment the
udp packet ?

-Ratheesh

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: UDP MSS
       [not found] <AANLkTi=qOQ0Rmyp78NEE9qSGOTFvgTDFSbDEDCtzoQ04@mail.gmail.com>
  2010-12-14  3:47 ` UDP MSS ratheesh k
@ 2010-12-14  4:00 ` Jan Engelhardt
  2010-12-14  6:01   ` ratheesh k
  2010-12-14 10:00   ` ratheesh k
  1 sibling, 2 replies; 10+ messages in thread
From: Jan Engelhardt @ 2010-12-14  4:00 UTC (permalink / raw)
  To: ratheesh k; +Cc: Netfilter mailing list

On Tuesday 2010-12-14 04:46, ratheesh k wrote:

>In udp , there is no mss discovey.So , if we  set DF bit in IP packet    and
>suppose an intermediate router does have disabled icmp-reply (thru iptables
>)  and  have less MTU than the sender.
>
>Then , router  will drop the packet ,How client know to fragment the  udp
>packet ?

It won't, that's why ICMP should not be blocked.

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: UDP MSS
  2010-12-14  4:00 ` Jan Engelhardt
@ 2010-12-14  6:01   ` ratheesh k
  2010-12-14 10:00   ` ratheesh k
  1 sibling, 0 replies; 10+ messages in thread
From: ratheesh k @ 2010-12-14  6:01 UTC (permalink / raw)
  To: Jan Engelhardt; +Cc: Netfilter mailing list

On Tue, Dec 14, 2010 at 9:30 AM, Jan Engelhardt <jengelh@medozas.de> wrote:
> On Tuesday 2010-12-14 04:46, ratheesh k wrote:
>
>>In udp , there is no mss discovey.So , if we  set DF bit in IP packet    and
>>suppose an intermediate router does have disabled icmp-reply (thru iptables
>>)  and  have less MTU than the sender.
>>
>>Then , router  will drop the packet ,How client know to fragment the  udp
>>packet ?
>
> It won't, that's why ICMP should not be blocked.
>

What will be the default  MSS .How is it determined ?

-ratheesh

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: UDP MSS
  2010-12-14  4:00 ` Jan Engelhardt
  2010-12-14  6:01   ` ratheesh k
@ 2010-12-14 10:00   ` ratheesh k
  2010-12-14 12:21     ` John Haxby
  1 sibling, 1 reply; 10+ messages in thread
From: ratheesh k @ 2010-12-14 10:00 UTC (permalink / raw)
  To: Jan Engelhardt; +Cc: Netfilter mailing list

How udp determines maximum sustainable  MSS ?

On Tue, Dec 14, 2010 at 9:30 AM, Jan Engelhardt <jengelh@medozas.de> wrote:
> On Tuesday 2010-12-14 04:46, ratheesh k wrote:
>
>>In udp , there is no mss discovey.So , if we  set DF bit in IP packet    and
>>suppose an intermediate router does have disabled icmp-reply (thru iptables
>>)  and  have less MTU than the sender.
>>
>>Then , router  will drop the packet ,How client know to fragment the  udp
>>packet ?
>
> It won't, that's why ICMP should not be blocked.
>

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: UDP MSS
  2010-12-14 10:00   ` ratheesh k
@ 2010-12-14 12:21     ` John Haxby
  2010-12-14 13:40       ` ratheesh k
  0 siblings, 1 reply; 10+ messages in thread
From: John Haxby @ 2010-12-14 12:21 UTC (permalink / raw)
  To: ratheesh k; +Cc: Jan Engelhardt, Netfilter mailing list

On 14/12/10 10:00, ratheesh k wrote:
> How udp determines maximum sustainable  MSS ?

Unless I'm much mistaken, the concept doesn't apply.  UDP doesn't have 
an MSS and "maximum sustainable MSS" would imply a connection that isn't 
there are well.

jch


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: UDP MSS
  2010-12-14 12:21     ` John Haxby
@ 2010-12-14 13:40       ` ratheesh k
  2010-12-14 13:45         ` Jan Engelhardt
  0 siblings, 1 reply; 10+ messages in thread
From: ratheesh k @ 2010-12-14 13:40 UTC (permalink / raw)
  To: John Haxby; +Cc: Jan Engelhardt, Netfilter mailing list

On Tue, Dec 14, 2010 at 5:51 PM, John Haxby <john.haxby@oracle.com> wrote:
> On 14/12/10 10:00, ratheesh k wrote:
>>
>> How udp determines maximum sustainable  MSS ?
>
> Unless I'm much mistaken, the concept doesn't apply.  UDP doesn't have an
> MSS and "maximum sustainable MSS" would imply a connection that isn't there
> are well.
>
> jch
>
>

Coool .So udp fragmentation is done by ip layer.no mss.

-Ratheesh

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: UDP MSS
  2010-12-14 13:40       ` ratheesh k
@ 2010-12-14 13:45         ` Jan Engelhardt
  2010-12-14 14:18           ` ratheesh k
  0 siblings, 1 reply; 10+ messages in thread
From: Jan Engelhardt @ 2010-12-14 13:45 UTC (permalink / raw)
  To: ratheesh k; +Cc: John Haxby, Netfilter mailing list

On Tuesday 2010-12-14 14:40, ratheesh k wrote:

>On Tue, Dec 14, 2010 at 5:51 PM, John Haxby <john.haxby@oracle.com> wrote:
>> On 14/12/10 10:00, ratheesh k wrote:
>>>
>>> How udp determines maximum sustainable  MSS ?
>>
>> Unless I'm much mistaken, the concept doesn't apply.  UDP doesn't have an
>> MSS and "maximum sustainable MSS" would imply a connection that isn't there
>> are well.
>>
>> jch
>>
>>
>
>Coool .So udp fragmentation is done by ip layer.no mss.

Fragmentation is always done by the IP layer, even with
protocols like TCP.
You must mix up fragmentation and segmentation.

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: UDP MSS
  2010-12-14 13:45         ` Jan Engelhardt
@ 2010-12-14 14:18           ` ratheesh k
  2010-12-14 14:35             ` Jan Engelhardt
  0 siblings, 1 reply; 10+ messages in thread
From: ratheesh k @ 2010-12-14 14:18 UTC (permalink / raw)
  To: Jan Engelhardt; +Cc: John Haxby, Netfilter mailing list

On Tue, Dec 14, 2010 at 7:15 PM, Jan Engelhardt <jengelh@medozas.de> wrote:

> Fragmentation is always done by the IP layer, even with
> protocols like TCP.
> You must mix up fragmentation and segmentation.

Jan,

  what will be normal size of udp  segments ?

-Ratheesh

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: UDP MSS
  2010-12-14 14:18           ` ratheesh k
@ 2010-12-14 14:35             ` Jan Engelhardt
  2010-12-14 14:57               ` ratheesh k
  0 siblings, 1 reply; 10+ messages in thread
From: Jan Engelhardt @ 2010-12-14 14:35 UTC (permalink / raw)
  To: ratheesh k; +Cc: John Haxby, Netfilter mailing list

On Tuesday 2010-12-14 15:18, ratheesh k wrote:

>On Tue, Dec 14, 2010 at 7:15 PM, Jan Engelhardt <jengelh@medozas.de> wrote:
>
>> Fragmentation is always done by the IP layer, even with
>> protocols like TCP.
>> You must mix up fragmentation and segmentation.
>
>Jan,
>
>  what will be normal size of udp  segments ?

Counterquestion because yours does not seem to make sense: what is a 
normal size for TCP?

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: UDP MSS
  2010-12-14 14:35             ` Jan Engelhardt
@ 2010-12-14 14:57               ` ratheesh k
  0 siblings, 0 replies; 10+ messages in thread
From: ratheesh k @ 2010-12-14 14:57 UTC (permalink / raw)
  To: Jan Engelhardt; +Cc: John Haxby, Netfilter mailing list

On Tue, Dec 14, 2010 at 8:05 PM, Jan Engelhardt <jengelh@medozas.de> wrote:

> Counterquestion because yours does not seem to make sense: what is a
> normal size for TCP?
>
Jan,

I got it. Thanks  a ton.

-Ratheesh

^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2010-12-14 14:57 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
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     [not found] <AANLkTi=qOQ0Rmyp78NEE9qSGOTFvgTDFSbDEDCtzoQ04@mail.gmail.com>
2010-12-14  3:47 ` UDP MSS ratheesh k
2010-12-14  4:00 ` Jan Engelhardt
2010-12-14  6:01   ` ratheesh k
2010-12-14 10:00   ` ratheesh k
2010-12-14 12:21     ` John Haxby
2010-12-14 13:40       ` ratheesh k
2010-12-14 13:45         ` Jan Engelhardt
2010-12-14 14:18           ` ratheesh k
2010-12-14 14:35             ` Jan Engelhardt
2010-12-14 14:57               ` ratheesh k

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