SNAT Virtual Server is sending ICMP Destination Unreachable to Source Server

I compared your config with an outbound virtual server configuration that's working on one of our boxes. Some of the differences I noticed where the:

• Address translation and port translation is unchecked.
• We used a Fast Layer 4. We selected the all protocols option because we needed to SNAT more types of traffic.

ltm virtual /Common/website_outbound_vs {
description "Source nats the outbound connections of website server, so they exit with the IP of the VS"
destination /Common/0.0.0.0:0
mask any
profiles {
    /Common/fastL4 { }
}
source 10.88.100.116/32
source-address-translation {
    pool /Common/website_snatpool
    type snat
}
translate-address disabled
translate-port disabled
vlans {
    /Common/vlan_servers
}
vlans-enabled
}

ltm snat-translation /Common/10.88.100.43 {
address 10.88.100.43
inherited-traffic-group true
traffic-group /Common/traffic-group-1
}

ltm snatpool /Common/sitioweb_snatpool {
members {
    /Common/10.88.100.43
}