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DNS issues TC5.1.x

Tried to search for it in the Bug Toolkit and in the Forum, but did not find anything related.

I have an endpoint (c40, TC5.1.4) where DNS does not work. Its set up to use static ip and 2 static dns servers, as well as with the default gw.

The firewall guy told me he did not see any port 53 requests and I looked at a tcpdump on the endpoint

and can also confirm that. Interesting enough dns requests go from 127.0.0.1 to 127.0.0.1 port 53,

but not to the external defined ones.

I tried to remove the DNS and re-added them again, no change.

I noticed that the /etc/resolv.conf does not show any entries. (also a ping to a hostname fails).

Anyone stumbled across such an issue and has a tip?

Next step would be to do a factory default reset, but this would also kill the network connection, so I would need somebody on site.

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Cisco Employee

DNS issues TC5.1.x

Hello,

I am not sure what went wrong in the 1st place when one needs to manually go in an edit the files. I wonder whether the changes will survive a reboot of your system. When rebooting the filesystem and configs are created anew. If your reboot the system all remains working, I would say you are in good shape. If not, need to check the logfiles what went wrong where.

6 REPLIES
Cisco Employee

DNS issues TC5.1.x

Hello,

the script which configures DNS is S17resolvconf located at /etc/init.d :

[dderidde-ex90-home:/etc/init.d] $ ls S17resolvconf

S17resolvconf

[dderidde-ex90-home:/etc/init.d] $

It consults a few files to create the DNS environment. E.g. :

/config/sysconfig/network

/config/sysconfig/ipstack

/config/sysconfig/dns

/etc/resolv.conf.d/resolv4.conf

My /etc/resolv.conf file looks like this :

[dderidde-ex90-home:/etc/init.d] $ cat /etc/resolv.conf

# Generated by configupdater

nameserver 10.48.160.30

[dderidde-ex90-home:/etc/init.d] $

Can you check the files mentioned above and check their contents to see "what's there" ?

You can also look for any errors in the logfiles. E.g. :

cat /var/log/console | grep resolv

Do you have remote access to the device via a public address?

Regards,

Danny.

DNS issues TC5.1.x

Yes, I can reach it. I now manually edited the

[ep:/etc/init.d] $ cat /config/sysconfig/network

# This file is generated from parameters at

# Tue Aug 21 17:28:15 UTC 2012

METHOD=Static

IPSTACK="IPv4"

IPADDR=""

SUBNET="255.255.255.248"

GATEWAY=""

[ep:/etc/init.d] $ cat /config/sysconfig/ipstack

cat: /config/sysconfig/ipstack: No such file or directory

[ep:/etc/init.d] $ cat /config/sysconfig/dns

# This file is generated from parameters at

# Tue Aug 21 17:28:19 UTC 2012

DNSDOMAIN=""

NS1=#. .

NS2=

NS3=

NS4=

[ep:/etc/init.d] $ cat /etc/resolv.conf.d/resolv4.conf

# Generated by S17resolvconf

[

ep:/etc/init.d] $ cat /etc/resolv.conf

# Generated by configupdater

/config/sysconfig/dns file and added the settings and restarted

S17resolvconf which then created the resolf.conf file with the right content.

The endpoints seems to register fine now.

Is the endpoint now a "sane state" or is there something else I should do / fix?

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Cisco Employee

DNS issues TC5.1.x

Hello,

I am not sure what went wrong in the 1st place when one needs to manually go in an edit the files. I wonder whether the changes will survive a reboot of your system. When rebooting the filesystem and configs are created anew. If your reboot the system all remains working, I would say you are in good shape. If not, need to check the logfiles what went wrong where.

Re: DNS issues TC5.1.x

To see if it would be ok I rebooted the endpoint, but now it does not seem to come up again.

False alert, it was just icmp blocked in the firewall so I did not see it coming up again.

After the reboot the resolv.conf is still ok and the system is registered to our platform

(I rebooted the endpoint a couple of times before, which worked fine, there was no other config change done)

Thank you Danny!

Nachricht geändert durch Martin Koch

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Cisco Employee

DNS issues TC5.1.x

So, after you made your changes, the system was rebooted and then was no longer accessible?

A C40 can be accessed via console or via the remote control. You do seem to have root enabled, so you can use console, but that would require on-site presence to connect console cable and PC/MAC. Can you still access the system via On Screen Display menus controlled via remote control?

DNS issues TC5.1.x

Like I updated my old posting, that was just due to a ICMP block.

I am going to send you some more info in a private message.

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