VPN Connect to linksys WRT54G2 v1.5

I was issued a Cisco 881W router by my employer to use at home. The instructions say to connect it to my personal wireless router and then i should get a solid green “vpn” light on the issued rotuer. I am not getting the solid green light. However, if I connect the issued router directly to my cable modem, i do get the vpn light. Is there a setting on my personal wireless router that I need to change? VPN Passthroughs are already set to enable. Upnp is already enabled. I can connect to VPN wirelessly through my linksys router, but when I plug in the cisco 881w router to the linksys router (which is plugged into my cable modem) the VPN light won’t come on. I appreciate any help. Thanks.