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.
ronmar
Staff
Staff
Article Id 340903
Description This article provides a workaround for an ongoing issue on the FortiGate-80F-DSL installing /8 connected route.
Scope FortiGate-80F-DSL
Solution

An issue occurred on FortiGate-80F-DSL tested with v7.0.15, v7.2.9, v7.4.4, and v7.6.0 where the FortiGate is advertising a connected route of /8.

 

Sample routing table:

 

Routing table for VRF=0
S* 0.0.0.0/0 [5/0] via 192.168.13.1, wan2, [1/0]
C 169.0.0.0/8 is directly connected, dsl       <----- Automatic route installed.
C 169.254.2.0/24 is directly connected, dsl

 

This might cause an issue to have this /8 subnet traverse on another WAN interface.

 

Workaround:

Create two /9 static routes to override the /8 connected route. As /9 is a more specific route than /8, then it will override the current behavior where /8 is automatically installed.

 

To configure static route:

 

In CLI:

Create the 1st Subnet:

 

config router static

    edit 0

        set dst x.x.0.0/9       <----- Enter the Network Address of the connected route having an issue.

        set gateway Y.Y.Y.Y     <----- Enter the Gateway IP.

        set device *outgoing interface

    end

 

Create the 2nd Subnet:

 

edit 0
    set dst x.x.128.0/9
<----- Enter the Network Address of the connected route having an issue.
    set gateway x.x.x.x
<----- Enter the Gateway IP.
    set device *outgoing interface
end

 

In GUI:

Go to Network -> Static Routes  and select Create New.

 

Related article:

Technical Tip: How to create a static route on FortiGate from the GUI Interface