FortiGate
FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
MichaelTorres
Article Id 358160

 

Description

This article describes an issue where users are replicating an EMS Access topology in multiple FortiGates. One of the FortiGates is not working with the EMS access.

Scope

FortiGate.

Solution

Configuration.

The following configuration can be seen in FortiGate

 

VIP configuration:

 

edit "Server"
    set type access-proxy
    set extip 192.168.10.2
    set extintf "any"
    set server-type https
    set extport 26444
    set ssl-certificate "Fortinet_Factory"
next

 

Access proxy:

 

edit "Server"
    set vip "Server"
        config api-gateway
            edit 1
                set url-map "/tcp"
                set service tcp-forwarding
                    config realservers
                        edit 1
                            set address "ZTNA-SJ"
                            set domain "domain.com"

 

To identify the issue, run the following debugs in the FortiGate :

 

SJOFW01 # di de console timestamp enable

SJOFW01 # di wad debug enable category all
Debug messages will be on for 30 minutes.

SJOFW01 # di wad debug enable level verbose
Debug messages will be on for 30 minutes.

SJOFW01 # di de en

 

In the debugs, search for the wad_http_req_dns :

 

[V]2024-10-30 15:56:28.610184 [p:17042]               wad_dns_parse_name_resp           :323   domain.com: resp_type=0 notify=1 cdata=0 N/A
[I]2024-10-30 15:56:28.610187 [p:17042][s:3930806603][r:67109425] wad_vs_proxy_dns_request_done     :3022  req(0x7f7ce3d35828) vs DNS resolved: N/A
[V]2024-10-30 15:56:28.610193 [p:17042][s:3930806603][r:67109425] wad_tcp_port_out_read_block       :1005  tcp_port 0x7f7ce3e82048 fd=50 on=0 n_out_block=1~>0 in(/out)_shutdown=0/0 closed=0 state=2.
[V]2024-10-30 15:56:28.610195 [p:17042][s:3930806603][r:67109425] wad_tcp_port_transport_read_block :960   tcp_port 0x7f7ce3e82048 fd=50 on=0 n_out_block=1~>0 in(/out)_shutdown=0/0 closed=0 events=0x1.
[V]2024-10-30 15:56:28.610197 [p:17042][s:3930806603][r:67109425] wad_http_msg_strm_resume          :1088  strm resumed, execute=wad_http_clt_read_req_line is_clt=1
[I]2024-10-30 15:56:28.610199 [p:17042][s:3930806603][r:67109425] wad_http_req_exec_on_vs_dns_ready :12458 req(0x7f7ce3d35828) vs DNS ready: dns_resolved(0), domain_matched(1), addr_matched(0)
[V]2024-10-30 15:56:28.610200 [p:17042][s:3930806603][r:67109425] wad_http_req_dns_fail             :12420 req(0x7f7ce3d35828) vs DNS failed.

 

In the FortiGate DNS settings, public DNS servers are configured:

 

config system DNS
    set primary 8.8.8.8
    set secondary 8.8.4.4
end

 

Solution:  

Change the FortiGate DNS server to the internal network DNS servers.