Update readme and manpage

This commit is contained in:
Erik Ekman 2009-07-16 09:12:20 +00:00
parent f1f7faee70
commit b44aaf2982
2 changed files with 22 additions and 5 deletions

20
README
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@ -64,15 +64,25 @@ be able to ping the other end of the tunnel from either side.
MISC. INFO:
Try experimenting with the MTU size (-m option) to get maximum bandwidth. It is
set to 1024 by default, which seems to work with most DNS servers. If you have
problems, try setting it to 220 as this ensures all packets to be < 512 bytes.
Some DNS servers enforce a 512 byte packet limit, and this is probably the case
if you can ping through the tunnel but not login via SSH.
Routing:
The normal case is to route all traffic through the DNS tunnel. To do this, first
add a route to the nameserver you use with the default gateway as gateway. Then
replace the default gateway with the servers IP address within the DNS tunnel,
and configure the server to do NAT.
MTU issues:
These issues should be solved now, with automatic fragmentation of downstream
packets. There should be no need to set the MTU explicitly on the server.
If you have problems, try inspecting the traffic with network monitoring tools
and make sure that the relaying DNS server has not cached the response. A
cached error message could mean that you started the client before the server.
The -D option on the server can also show received and sent queries.
The iodined server replies to NS requests sent for subdomains of the tunnel
domain. If your domain is tunnel.com, send a NS request for foo.tunnel.com
to see if the delegation works. dig is a good tool for this:
dig -t NS foo123.tunnel.com
The upstream data is sent gzipped encoded with Base32, or Base64 if the relay
server support '+' in domain names. DNS protocol allows one query per packet,

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@ -229,6 +229,13 @@ add a route to the nameserver you use with the default gateway as gateway. Then
replace the default gateway with the servers IP address within the DNS tunnel,
and configure the server to do NAT.
.TP
.B Troubleshooting:
Use the \-D option on the server to show received and sent queries, or a
tool like Wireshark/tcpdump. The iodined server replies to NS requests sent for
subdomains of the tunnel domain. If your domain is tunnel.com, send a NS
request for foo.tunnel.com to see if the delegation works. dig is a good tool
for this: dig \-t NS foo123.tunnel.com
.TP
.B MTU issues:
These issues should be solved now, with automatic fragmentation of downstream
packets. There should be no need to set the MTU explicitly on the server.