Hello Nanog,
I am trying get zone trasfer from a host, but it seems that because of
firewals?, I can not get any record.
They acknowelged that there is a host behind the firewalls but they claim
it should not affect it. (I don't believe it.)
But I don't know how to check/prove that if certain host can
receive/send an UDP packet.
Zone transfers are handled via TCP, not UDP. See if you
can telnet to port 51 on their nameserver; if you can't
get a connection established, you won't be able to do
a zone transfer.
TIA,
Tatsuya
Matt
>
> Hello Nanog,
>
> I am trying get zone trasfer from a host, but it seems that because of
> firewals?, I can not get any record.
> They acknowelged that there is a host behind the firewalls but they claim
> it should not affect it. (I don't believe it.)
> But I don't know how to check/prove that if certain host can
> receive/send an UDP packet.
Zone transfers are handled via TCP, not UDP. See if you
can telnet to port 51 on their nameserver; if you can't
get a connection established, you won't be able to do
a zone transfer.
I think you mean port 53. This is both TCP and UDP. I thought DNS
used both TCP and UDP. Thus firewall that is blocking UDP traffic will
cause zone updates to fail.
name 42/udp nameserver
whois 43/tcp nicname # usually to sri-nic
domain 53/tcp
domain 53/udp
Cheers
Date: Sun, 27 Sep 1998 21:11:32 -0700 (PDT)
From: Matthew Petach <mpetach@netflight.com>
To: Tatsuya Kawasaki <tatsuya@giganet.net>
Cc: nanog@merit.edu
Subject: Re: UDP packet/DNS server
>
> Hello Nanog,
>
> I am trying get zone trasfer from a host, but it seems that because of
> firewals?, I can not get any record.
> They acknowelged that there is a host behind the firewalls but they claim
> it should not affect it. (I don't believe it.)
> But I don't know how to check/prove that if certain host can
> receive/send an UDP packet.
Zone transfers are handled via TCP, not UDP. See if you
can telnet to port 51 on their nameserver; if you can't
That's port 53...
get a connection established, you won't be able to do
a zone transfer.
> TIA,
> Tatsuya
Matt
Mathias Koerber | Tel: +65 / 471 9820 | mathias@staff.singnet.com.sg
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I think you mean port 53. This is both TCP and UDP. I thought DNS
used both TCP and UDP. Thus firewall that is blocking UDP traffic will
cause zone updates to fail.
name 42/udp nameserver
whois 43/tcp nicname # usually to sri-nic
domain 53/tcp
domain 53/udp
Queries are done via UDP; zone transfers are always fully TCP.
ag