Hairpin Routing on ZTE ZXV10 W300

Internet access discussion, including Fusion, IP Broadband, and Gigabit Fiber!
7 posts Page 1 of 1
by whorfin » Sat Jun 02, 2012 2:35 pm
Support came up empty, telling me ZTE is a terrible to sonic as they are to me,
and has not provided them with manuals. This seems a bit strange to me, since
the ZTE came pre-configured with several functions pointing to sonic.net domains.
In any event:
I run a number of services in the home, such as home automation and data
access. This requires either port forwarding
or a virtual server. I could find no port forwarding on the ZTE,
so I set up a virtual server. Unfortunately, the router seems not
to support hairpin routing.

ie, if the inside address of a security camera [for example] is, let's say,
192.168.0.66, and i've set up a virtual server to port
[let's say] 1234. Then from the outside [internet],
blahblah.dyndns.org:1234 is correctly forwarded.
From the inside, 192.168.0.66:1234 also works fine [i'd hope so].
But from the inside, blahblah.dyndns.org:1234 does not work.
Resolving this to the external IP and doing [for example]
50.0.74.166:1234 also works from outside but not inside,
so this is not related to dyndns

This is, basically, a "hairpin routing" problem. I
have had previous routers where "virtual server" configurations
fail to hairpin route but "port forwarding" succeeds. I
don't know if this router is similar, but while some of the
manuals on the internets show a port forward page for this device,
i don't see one; the GUI looks quite a bit different from what i've
seen on the manuals circulating on the intertubes.

So the question: is there any way to get hairpin routing to work?
Port forwarding, NAT, routing tables, firmware update --- anything?
Or a manual so i can figure it out myself?

Modem reports:
Firmware Version: W300V3.1.0a_DR0_OV
by wifi » Sun Jun 03, 2012 9:34 am
try searching the web for zxv10 and "nat loopback"
hopefully this helps ..
http://www.google.com/search?hl=en&as_q ... t+loopback
by whorfin » Sun Jun 03, 2012 12:25 pm
Thank you "wifi"!!
Now that I know this thing is running ZyNOS, all becomes clear...

For those of you in my boat, here is the magic. Set up
a "virtual server" as desired, then do the below to enable
hairpin routing:

telnet [ip address of your ZTE modem]
ip nat loopback on
exit

This should solve your problem, but it will not survive a power cycle.
Verify this works for you. To make it permanent, you need stronger
magic. Proceed at your own risk... () denote parenthetical
comments from me.

FIRST backup a rom-0, in case you mess up, restoring this will over-write
any changes to autoexec.net you make. once you change that file
via "sys edit" a new rom-0 backup will contain those changes.

telnet [ip address of your ZTE modem]
sys edit autoexec.net
(you will see:
EDIT cmd: q(uit) x(save & exit) i(nsert after) d(elete) r(eplace) n(ext)
)
i (type "i" to enter insert mode, as you type you'll see a ":" prompt)
ip nat loopback on
x (after the carriage return above, type "x" to save & exit)
sys view autoexec.net
(this should show you your "ip nat loopback on" sitting at the start of the file; you can
go through sys edit again and "d" the line if you want to turn it back off; careful not
to muck with that file!)
exit

Cheers
--Rick
by Jim » Fri Jul 20, 2012 12:38 pm
Thanks Rick!! This solved my port forwarding problem for my security camera!
by Emi Silva » Fri Jan 03, 2014 11:05 am
This was really, really useful. Thank you a lot.
by shaban » Sun Mar 23, 2014 1:32 pm
wifi wrote:try searching the web for zxv10 and "nat loopback"
hopefully this helps ..
http://www.google.com/search?hl=en&as_q ... t+loopback
by lcarver » Sat Jul 19, 2014 1:22 pm
I have configured port forwarding on various occasions over the years; but not often.
Now, I have set up a network video recorder (NVR) at my home and defined three service ports
to be forwarded in from the outside to the NVR. Everything looked correct, in fact I used a software tool
to get the commands in easier/quickly to the ZXV10, and verified correctness a few times.
But I could not fathom why traffic simply would not forward in to my desired node.

I was reminded of the existence of these forums (I've been a Sonic.net Fusion DSL customer for a couple of years),
and within a couple of minutes I found your post.
Whorfin, your advice ( ip nat loopback on ) was perfect !
And I've inserted the line in autoexec.net on the ZXV10 as well.
This is a relief. Am very happy to have found this info ... thanks again. Larry
7 posts Page 1 of 1