Your router seems to have an internal firewall:
Belkin Wireless G Plus MIMO Router
The Belkin Wireless G Plus MIMO Router offers features similar to those of the Belkin Pre-N router but with slower performance. On the upside, it's also less expensive.
Specs: Wired, Wireless, 108 Mbps, Fast Ethernet, Ethernet, IEEE 802.11g, IEEE 802.11b, Ethernet, Wi-Fi CERTIFIED, IEEE 802.11g, IEEE 802.11b, External, VPN passthrough, Stateful Packet Inspection (SPI), DHCP support, NAT support,
Firewall protection, True MIMO technology, MAC address filtering, 2.4 GHz
I assume you see a brickwall in front of the small globe in the bottom right corner.
Follow this link on how to configurate it
http://www.gnutellaforums.com/showthread.php?t=51361