Losing connection to local connected DNS when VPN is active

[FortiJeroen]

Hi all, I ran into the following issue using FortiClient VPN for MacOS. All MacOS clients are on the network 10.100.1.0/24, within this network there is also DHCP/DNS-Cache/gateway host (10.100.1.33). This is working fine until you setup the SSLVPN connection, then the connection to 10.100.1.33 is not functional anymore. Routing table before setup SSLVPN, (netstat -nr | grep 10.100.1.33) netstat -nr | grep 10.100.1.33 10.100.1.33 0:c:29:d8:32:ae UHLWIi en0 1036 10.100.3/24 10.100.1.33 UGSc en0 Routing table after setup SSLVPN, (netstat -nr | grep 10.100.1.33) netstat -nr | grep 10.100.1.33 10.100.1.33/32 10.100.1.1 UGSc en0 10.100.3/24 10.100.1.33 UGSc en0 (from here the 10.100.1.33 is unreachable anymore) I only see this issue when using the MacOS version of the VPN client, tested with version: 6.2.2.680 - interim 6.2.2.685 Setup the SSLVPN is done with a split-tunnel config, in the config their is no relation with the 10.100.1.0/24 subnet. My question is, why is the entry in the routing table changed when setup the VPN, i can’t see the relation why this is done. Also the VPN client logging is not specifying any useful information. 20191204 09:06:06.469 [sslvpn:INFO] unknown:0 blocked all ipv6 traffic 20191204 09:06:06.469 [sslvpn:INFO] unknown:0 begin io loop 20191204 09:06:06.470 [sslvpn:INFO] unknown:0 launch ssl read thread 20191204 09:06:06.470 [sslvpn:INFO] unknown:0 launch tty read thread 20191204 09:06:06.470 [sslvpn:INFO] unknown:0 ssl read thread started 20191204 09:06:06.471 [sslvpn:INFO] unknown:0 main thread waiting for threads termination 20191204 09:06:06.471 [sslvpn:INFO] unknown:0 ssl write thread started 20191204 09:06:06.471 [sslvpn:INFO] unknown:0 tty read thread started 20191204 09:06:06.472 [sslvpn:INFO] unknown:0 tty write thread started 20191204 09:06:07.309 [sslvpn:INFO] unknown:0 got peer's ip address 20191204 09:06:07.539 [sslvpn:INFO] unknown:0 ppp interface is up 20191204 09:06:07.541 [sslvpn:INFO] unknown:0 Current dns 0: 10.100.1.33 20191204 09:06:07.542 [sslvpn:INFO] unknown:0 No wins is set currently 20191204 09:06:08.609 [sslvpn:INFO] unknown:0 try to get ppp's ip address 10.232.4.32 20191204 09:06:08.612 [sslvpn:INFO] unknown:0 no DNS configured on fgt, keep current DNS, ret = 0 20191204 09:06:08.635 [sslvpn:INFO] unknown:0 split tunnel is specified 20191204 09:06:08.635 [sslvpn:INFO] unknown:0 defalt gateway: 10.100.1.1:en0 20191204 09:06:08.644 [sslvpn:INFO] unknown:0 Split: 85.x.x.x/32 Hope some of you can help tackle this issue, thanks in advance. Jeroen