Error [failed to parse dns req packet] when multiple DNS servers configured on GlobalProtect
19807
Created On 01/31/23 10:37 AM - Last Modified 06/23/23 23:12 PM
Symptom
- Seeing the following logs in GlobalProtect logs from the client
(P6768-T31172)Debug( 917): 10/05/22 08:55:50:062 HandleDnsCallback: failed to parse dns req packet. (P6768-T31172)Debug( 917): 10/05/22 08:55:50:152 HandleDnsCallback: failed to parse dns req packet. (P6768-T31172)Debug( 917): 10/05/22 08:55:55:155 HandleDnsCallback: failed to parse dns req packet. (P6768-T31172)Debug( 917): 10/05/22 08:56:05:156 HandleDnsCallback: failed to parse dns req packet. (P6768-T31172)Debug( 917): 10/05/22 08:56:05:217 HandleDnsCallback: failed to parse dns req packet. (P6768-T31172)Debug( 917): 10/05/22 08:56:05:264 HandleDnsCallback: failed to parse dns req packet. (P6768-T31172)Debug( 917): 10/05/22 08:56:10:269 HandleDnsCallback: failed to parse dns req packet. (P6768-T31172)Debug( 917): 10/05/22 08:56:10:345 HandleDnsCallback: failed to parse dns req packet.
- Packet captures showing DNS requests sent to both servers but no reply from the secondary
Environment
- GlobalProtect configured w/ multiple DNS servers
- Windows host machine
Cause
The secondary DNS server never responds resulting in the webpage constantly waiting to load
Resolution
- Remove the non-responsive DNS server from the GP configuration.
- If required, consider using a public facing DNS server as the backup