Hello all,I am currently trying to configure Sophos xg to replace my Fritzbox.From problems with certificates, I have become aware that my DNS resolution for internal hosts and the xg itself is not working.Currently I have only a test client, which has the xg entered as the default gateway and DNS server.When accessing blocked websites I always had problems with the certificate and had read somewhere that I should choose the hostname of the firewall as redirection page so that there are no problems with the CN.Here I found out that I can not make a ping on the name of the XG. Now I added the XG as DNS-HOST, but it still does not work. Also other host, which are meanwhile also registered as DNS host I can not reach via ping.Does anyone have an idea what I have configured wrong?Many greetingsMarc
the first step would be to check if DNS is allowed on the Zone.
An other useful thing is packet capture
you can see if and probably why something like DNS is blocked
DNS is enabled in the zone LAN
Here is the result from the packet capture. Where can I see here if it has been blocked?
Here is the result of nslookup:
nslookup schneckenxgDNS request timed out. timeout was 2 seconds.Server: UnKnownAddress: 172.16.0.2Nicht autorisierende Antwort:DNS request timed out. timeout was 2 seconds.Name: schneckenxgAddress: 172.16.0.2
172.16.0.2 is the LAN Interface172.16.3.103 is the client
please try adding you XG into the Network -> DNS -> DNS host entry table.
DNS Host was already added:
Any other idea?
Please post a copy of your DNS setup, there appears to be an issue with the XG DNS configuration. Also check the DNS setting on your test device.
hopefully here are all the information:
Have I forgotten a configuration? I'm currently having a bit of trouble with the configuration. I had administered an asg8 years ago.
thank you for all there screenshots.
The XG should be using an external DNS, where you would add the XG as an internal DNS is in the DHCP settings.
Hello Ian,is it not possible to have only the XG as DNS server?
Yes, it is but on the internal side not the external side. You need to provide some external DNS access to resolve lookups.
thanks for the answer
Doesn't the lookup of external names work automatically via the WAN interface? I am not sure what I need to change.
Sorry for possible stupid questions.
But, you have told the WAN interface to use the internal address of the XG as its lookup.
In the DNS settings change the DNS to use DHCP settings for the WAN interface or used fixed as you have.
I have mine set to use my ISP's DNS IP4 and IPv6, alot of people use 184.108.40.206 or 220.127.116.11 or 18.104.22.168 which are a mix of Google and Cloudflare DNS.
now I changed DNS 1 to 22.214.171.124 and the dns query configuration
The network configuration on my client looks like this:
IPv4-Adresse . . . . . . . . . . : 172.16.3.100 Subnetzmaske . . . . . . . . . . : 255.255.248.0 Standardgateway . . . . . . . . . : 172.16.0.2 (XG) DNS-Server . . . . . . . . . . . : 172.16.0.2(XG)
Unfortunately, it still doesn't work. Even ipconfig /flushdns on the client does not help.
Please remove the 127 address, that is an internal nonevroutable address and should not be on the external interface.
then allow time for the XG to update its tables.
Hi Ian,I have now removed 127 and waited about 3 hours. Unfortunately without success. Restarting the XG does not work either.What I notice is that when I execute the following command on my client, a DNS error occurs: netsh interface ipv4 set dnsservers name="Ethernet 2" static 172.16.0.2 The configured DNS server is incorrect or does not exist. Any idea?
from your screenshots the XG is now using 126.96.36.199 as primary DNS. It should now be able to resolve names on it's own.
btw. the 127.0.0.1 should be OK to stay there as second resolver. This would be the only way to resolve names, that are only configured on the XG with static mappings.
On XG when you go to diagnostic > tools > name lookup
Select lookup using all configured servers
can you resolve external FQDN?
external FQDN works fine
and can the lan machines resolve external DNS, too?
In the screenshots you posted, you use something like
have you tried using a FQDN like schneckenXG.mydomain.local -> 172.16.0.2
Packet Capture looks good.
These are static DNS HOSTS to test a host other than just the XG.I can ping other external hosts. Unfortunately, an attempt with an FQDN "schneckenXG.schneckenhaus.local" did not help either:
"schneckenhaus.local" is defined in my dhcp-Server:
LHerzog said:btw. the 127.0.0.1 should be OK to stay there as second resolver. This would be the only way to resolve names, that are only configured on the XG with static mappings.
This is not correct, if you are using the XG as your internal DNS. The external FQDN is different to the internal FQDN and there appears to be a firewall rule allowing LAN devices totally to the external DNS and not use the internal DNS looking at the PCAP result.
There is no real reason to allow users to use external DNS when you have better security using the XG DNS, that is one less exposure point.