dhp renew
Chresten
to allocate a IP to the ROUTER.
Some time(most of the time), when the is a renew(dhcp), on the wan side
off the router, from/to the ISP.
At that instant i loose the TCP connection, it simple stop. An it is
only when there is a renew, i loose the connection.
UDP an other type of connection is function OK, all the time. The ISP
wont extend the dhcp renew time(1/2 hour).
What can i do ???
:)
-C
Barry Margolin
Chresten <chre...@bb.aa> wrote:
Does your IP change when the renew happens? TCP connections are keyed
off the IP, so a connection can't be maintained across an IP change.
Normally, a DHCP renewal should retain the same IP, unless the ISP is
reorganizing their IP space and the old IP is no longer available.
Another possibility is that there's a bug in your router, that it clears
out its NAT table whenever there's a DHCP renewal, even if the IP hasn't
changed. Make sure you have the latest firmware, and if that doesn't
help get a new router.
--
Barry Margolin, bar...@alum.mit.edu
Arlington, MA
*** PLEASE don't copy me on replies, I'll read them in the group ***
Chresten
is the same all the time. there is the same router for the 2 line, and
the problem is only on one line. And i have updatet the firmeware on the
Linksys router. And i have switch the router round.
:)
C
Chresten
drop UDP 'connection'?
:)
C
glen herrmannsfeldt
> Well it is a static IP(dhcp). Or at least i pay for a static IP, and it
> is the same all the time. there is the same router for the 2 line, and
> the problem is only on one line. And i have updatet the firmeware on the
> Linksys router. And i have switch the router round.
In that case, just put a static address into the router.
Avoid DHCP all together.
-- glen
glen herrmannsfeldt
> And if it is dropping the NAT table, then is it not, most likely
> also to drop UDP 'connection'?
UDP is, at least at the IP level, connectionless.
If any requests (assuming client/server) are outstanding then
the replies will be lost. The requestor will then try again,
the new translation entry will be added, and things will continue
on as usual. At least that is the way most UDP related services go.
If the server application keeps state based on the source
address then it will fail, but most don't.
-- glen
Chresten
:)
C
Chresten
a renew(dhcp)(1/2 hours)...
:)
C
Jorgen Grahn
On Wed, 2009-10-14, Chresten wrote:
> Chresten wrote:
>> glen herrmannsfeldt wrote:
>>> Chresten <chre...@bb.aa> wrote:
>>>
>>>> Well it is a static IP(dhcp). Or at least i pay for a static IP, and
>>>> it is the same all the time. there is the same router for the 2
>>>> line, and the problem is only on one line. And i have updatet the
>>>> firmeware on the Linksys router. And i have switch the router round.
>>>
>>> In that case, just put a static address into the router.
>>>
>>> Avoid DHCP all together.
>>>
>>> -- glen
>> Well; of course.... thanks
> oh no.. for some reason, the ISP don't allowed static IP, there must be
> a renew(dhcp)(1/2 hours)...
You say you pay for a static IP, but the ISP doesn't allow it? Then
they owe you some money, I think ...
(Oh, I guess they can call it "static" if they promise to give you
the same address every time. But I'm happy my static address doesn't
work that way.)
/Jorgen
--
// Jorgen Grahn <grahn@ Oo o. . .
\X/ snipabacken.se> O o .
Barry Margolin
Chresten <chre...@bb.aa> wrote:
> And if it is dropping the NAT table, then is it not, most likely also to
> drop UDP 'connection'?
> :)
UDP doesn't have connections. Every time you send an outgoing packet it
will create a new NAT entry for it if there isn't one already.
David Schwartz
> UDP doesn't have connections. Every time you send an outgoing packet it
> will create a new NAT entry for it if there isn't one already.
Right, so even if is loses the NAT entry, as soon as there's another
outgoing packet, it will reform. So you may notice minor disruptions,
but you probably won't lose "connections". In effect, each outbound
packet forms a new "connection".
With TCP, if the NAT entry is lost, so is the state required to NAT
the TCP connection. The TCP connection is lost until it is fully re-
established. That likely won't happen without consequences visible at
the application layer.
I think Barry is right, your router likely has a bug that causes it to
flush the NAT table when it gets a "new" IP address even if the "new"
IP address is the same.
If that's not it, it's possible the router can't support a lease time
as short as 30 minutes (and so fails to renew early enough). This can
happen with DHCP clients coded to always renew 30 minutes before
expiration. Since it's never 30 minutes before expiration (always a
tiny bit less) they never trigger a renew.
Make sure your IP address isn't changing.
One other tip -- your router can be configured to claim its own IP
address or accept whatever the peer sends. You should get the same
result either way if you have a static IP address -- the peer should
always offer you the same address you would ask for. But it may help
to flip around the way you do it. If you didn't configure the WAN IP,
configure it. If you did, set it to accept the peer's assigned IP.
That might get around the issue, whatever it is.
DS
Martijn Lievaart
On Wed, 14 Oct 2009 22:19:42 +0200, Chresten wrote:
> Chresten wrote:
>> glen herrmannsfeldt wrote:
>>> Chresten <chre...@bb.aa> wrote:
>>>
>>>> Well it is a static IP(dhcp). Or at least i pay for a static IP, and
>>>> it is the same all the time. there is the same router for the 2
>>>> line, and the problem is only on one line. And i have updatet the
>>>> firmeware on the Linksys router. And i have switch the router round.
>>>
>>> In that case, just put a static address into the router.
>>>
>>> Avoid DHCP all together.
>>>
>> Well; of course.... thanks
>> :)
> oh no.. for some reason, the ISP don't allowed static IP, there must be
> a renew(dhcp)(1/2 hours)...
> :)
What happens when you just do it? I give you a good chance it works.
M4
Chresten
i entreaty the static IP(from ISP) yesterday in the Linksys router, at
first et work fine, but after som time the line went down. Ant i
couldn't ping the ISP's gateway, or get any connection on the line.
it was up fore ~½ hour.
:)
C
Barry Margolin
Chresten <chre...@bb.aa> wrote:
> it was up fore ~1⁄2 hour.
> :)
> C
It sounds like the ISP is using the DHCP renewal messages as a form of
keepalive for the DSL connection. That's probably why they set the
lease time so short, they want to detect when you've gone away quickly,
so the DSLAM can clean up the session.