Skip to main content

domain name system - Vyatta and DNS Rewrite (aka hairpin or doctoring)



I'm trying to make my public IP reachable also from inside LAN.



I know that it's better to spilt DNS in order to have an internal zone that solves hosts with internal IP, but for a lot of reasons this is not applicable to my environment.



I have a "simple" configuration, a server and few NAT ports:




set nat destination rule 4002 description 'NAT inbound'
set nat destination rule 4002 destination address 'x.y.z.k'
set nat destination rule 4002 destination port '80,443,10050,10051,11051'
set nat destination rule 4002 inbound-interface 'bond1'
set nat destination rule 4002 protocol 'tcp'
set nat destination rule 4002 translation address '10.0.0.190'

set nat source rule 4002 description 'NAT outbound'
set nat source rule 4002 outbound-interface 'bond1'

set nat source rule 4002 source address '10.0.0.190'
set nat source rule 4002 translation address 'x.y.z.k'


When I try to access the public IP from internal network I cannot reach it. It's a problem similar to How to implement Nat loopback/reflection?



I've found a solution here: http://onebadpixel.com/blog/2014/01/22/part-5-nat-translation/



And so I've tried to add this to configuration:




set nat source rule 1000 description 'NAT hairpin'
set nat source rule 1000 destination address '10.0.0.128/24'
set nat source rule 1000 outbound-interface 'bond0'
set nat source rule 1000 source address '10.0.0.128/24'
set nat source rule 1000 translation address 'masquerade'


But it still don't work.



Any suggestion on how to change my configuration in order to use DNS hairpin?




I'm not expert in Vyatta, I came from Cisco ASA world where it was easy... just add "dns" on the NAT rule ;)



Thanks
Fabio


Answer



You can view an example here (answer from SteveP):



http://forum.vyos.net/showthread.php?tid=6554




(VyOs is an open source fork of Vyatta and this should be applicable)



Note the the hairpin is done through a nat destination rule and not a nat source.



NAT destination change the destination IP address (which is what you need in this case) and is performed prior to the routing decision while NAT source rewrite the source IP address is processed after the routing decision.



Also in your configuration "10.0.0.128/24" is curious. You should use either 10.0.0.0/24 for the network or 10.0.0.128 for the host.


Comments

Popular posts from this blog

linux - iDRAC6 Virtual Media native library cannot be loaded

When attempting to mount Virtual Media on a iDRAC6 IP KVM session I get the following error: I'm using Ubuntu 9.04 and: $ javaws -version Java(TM) Web Start 1.6.0_16 $ uname -a Linux aud22419-linux 2.6.28-15-generic #51-Ubuntu SMP Mon Aug 31 13:39:06 UTC 2009 x86_64 GNU/Linux $ firefox -version Mozilla Firefox 3.0.14, Copyright (c) 1998 - 2009 mozilla.org On Windows + IE it (unsurprisingly) works. I've just gotten off the phone with the Dell tech support and I was told it is known to work on Linux + Firefox, albeit Ubuntu is not supported (by Dell, that is). Has anyone out there managed to mount virtual media in the same scenario?

hp proliant - Smart Array P822 with HBA Mode?

We get an HP DL360 G8 with an Smart Array P822 controller. On that controller will come a HP StorageWorks D2700 . Does anybody know, that it is possible to run the Smart Array P822 in HBA mode? I found only information about the P410i, who can run HBA. If this is not supported, what you think about the LSI 9207-8e controller? Will this fit good in that setup? The Hardware we get is used but all original from HP. The StorageWorks has 25 x 900 GB SAS 10K disks. Because the disks are not new I would like to use only 22 for raid6, and the rest for spare (I need to see if the disk count is optimal or not for zfs). It would be nice if I'm not stick to SAS in future. As OS I would like to install debian stretch with zfs 0.71 as file system and software raid. I have see that hp has an page for debian to. I would like to use hba mode because it is recommend, that zfs know at most as possible about the disk, and I'm independent from the raid controller. For us zfs have many benefits,

apache 2.2 - Server Potentially Compromised -- c99madshell

So, low and behold, a legacy site we've been hosting for a client had a version of FCKEditor that allowed someone to upload the dreaded c99madshell exploit onto our web host. I'm not a big security buff -- frankly I'm just a dev currently responsible for S/A duties due to a loss of personnel. Accordingly, I'd love any help you server-faulters could provide in assessing the damage from the exploit. To give you a bit of information: The file was uploaded into a directory within the webroot, "/_img/fck_uploads/File/". The Apache user and group are restricted such that they can't log in and don't have permissions outside of the directory from which we serve sites. All the files had 770 permissions (user rwx, group rwx, other none) -- something I wanted to fix but was told to hold off on as it wasn't "high priority" (hopefully this changes that). So it seems the hackers could've easily executed the script. Now I wasn't able