Forum Discussion
hc_andy_35682
Nimbostratus
NimbostratusConnectivity Issue Between Hosts & Real Servers in the same VLAN
Hi All,
As a test, I've set up a Virtual Server on the F5 to load balance HTTP traffic to two real servers in Vlan 502.
F5 (Active) --> core1
F5 (Standby) --> core2
There is a cross over from core1 to core2. And imagine a cloud to the right of the cores which represent the Vlans.
My issue is that hosts in the same Vlan can not access services/applications of real servers (which are also in the same vlan) when access is made via the Virtual Server IP. Access to the Virtual Server IP from other Vlans works a treat. Is there an issue with my forwarding VIP???
When a host from the same Vlan502 (eg:10.15.210.200/24) makes a connection to the Virtual Server IP 10.15.254.222/32, the connection just drops.
> telnet 10.15.254.222 80
Trying 10.15.254.222...
Connected to 10.15.254.2221.
Escape character is '^]'.
Connection closed by foreign host.
- Snippet of config shown below
- BIG-IP LTM, version 10.1.0
- Outside Vlan80
- Inside Vlan502
pool VMTEST_HTTP_POOL {
monitor all gateway_icmp and http
members {
10.15.210.84:http {}
10.15.210.85:http {}
}
}
virtual address 10.15.210.0 {
mask 255.255.255.0
}
virtual INSIDE_VLAN502 {
ip forward
destination 10.15.210.0:any
mask 255.255.255.0
vlans Vlan_80 enable
}
virtual VMTEST_HTTP {
pool VMTEST_HTTP_POOL
destination 10.15.254.222:http
ip protocol tcp
vlans Vlan_80 enable
}
virtual INSIDE_VLAN_TO_ANY_TCP {
pool VLAN80_HSRP_IP_POOL
destination any:any
mask 0.0.0.0
ip protocol tcp
vlans {
Vlan_502
} enable
}
virtual INSIDE_VLAN_TO_ANY_UDP {
pool VLAN80_HSRP_IP_POOL
destination any:any
mask 0.0.0.0
ip protocol udp
vlans {
Vlan_502
} enable
}
virtual INSIDE_VLAN_TO_ANY_ICMP {
ip forward
destination any:any
mask 0.0.0.0
ip protocol icmp
vlans {
Vlan_502
} enable
}
Thanks.
Andy
1 Reply
hc_andy_35682Argh worked it out...sort of...
This is because return traffic from the real servers does not go back to the F5 because the host making the connection and real servers are on the same subnet - so it doesn't forward the request back to the floating ip on the F5 which is it's default gateway.
Will probably need an iRule to SNAT traffic from hosts within the same Vlan/subnet so return traffic comes back to the F5.
