We are upgrading networking hardware in small network (less than 20 computers). It utilizes Windows Home Server on an Acer box as the file server. Internet<->DSL connection<-ethernet->NetGear Wireless/wired router<->Cisco switch<->LAN clients The Cisco switch has 16 ports, and all of the wired machines are normally connected to it. We don't expect to use the wired ports on the NetGear box. Starting in late the client machines started losing wired and wireless Internet connectivity, some machines lose connections to the Netgear router itself. One symptom seems to be related to new machine joining the network. Machine #2 connect using the wireless network, and machine #1 (previously connected) loses connectivity. The problem also existed with the older router, a LinkSys WRT54G unit that doesn't support 802.11n. I'd normally suspect a routing problem, and from one laptop I do see a preferred route for network 169.254.0.0. The NetGear router (a WNDR 3700) is configured with a static IP address and fixed DNS server settings, per arrangement with the ISP. These settings do provide internet connections, it's just that they are intermittent. The DSL line never seems to be losing connectivity, as the green light on the Willtel box stays on constantly. The NetGear router doesn't appear to have assigned the IP address associated with the 169.254 router (which is a ZeroConf address, normally associated with Apple's BonJour system.) I have three questions Q1) Why isn't there be a preferred route through the NetGear router (192.168.1.1)? There already seems to be a default route to 0.0.0.0 through the NetGear's IP address, with a metric of 10. There is persistent route advertised through 192.168.1.112 with a metric of 1 (see netstat output below). This strongly suggests either a misbehaving network device, or possibly a dual-homed machine elsewhere on the network spreading bogus routing, which isn't valid on this network. When this same laptop loses connectivity, the default route is hosed. I can no longer ping the router, and even wired connections fail. Ping 192.168.1.1: 192.168.1.2 Destination host unreachable (my machine itself unreachable) Ping 127.0.0.1: (works as expected) Q2) Could any ethernet-level settings (like Jumbo Frame support) be affecting wireless connections as well as wired ones? XP machines are similarly dropping network connections, so the problem isn't limited to Windows 7 machines. Q3) What troubleshooting tools are best in these situations? I can use ping and traceroute, but when the local system's IP address in unreachable, they aren't very effective. I have access to Linux systems and can configure static IP address on the local 192.168 network. Additional details (output of the netstat command): =========================================================================== Interface List 14...0c ee e6 9b 6c d1 ......Microsoft Virtual WiFi Miniport Adapter 12...0c ee e6 9b 6c d1 ......Dell Wireless 1397 WLAN Mini-Card 11...00 26 b9 08 68 2c ......Realtek PCIe GBE Family Controller 1...........................Software Loopback Interface 1 18...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #2 13...00 00 00 00 00 00 00 e0 Teredo Tunneling Pseudo-Interface 19...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #3 17...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #4 =========================================================================== IPv4 Route Table =========================================================================== Active Routes: Network Destination Netmask Gateway Interface Metric 0.0.0.0 0.0.0.0 192.168.1.1 192.168.1.2 10 127.0.0.0 255.0.0.0 On-link 127.0.0.1 306 127.0.0.1 255.255.255.255 On-link 127.0.0.1 306 127.255.255.255 255.255.255.255 On-link 127.0.0.1 306 169.254.0.0 255.255.0.0 192.168.1.112 192.168.1.2 11 192.168.1.0 255.255.255.0 On-link 192.168.1.2 266 192.168.1.2 255.255.255.255 On-link 192.168.1.2 266 192.168.1.255 255.255.255.255 On-link 192.168.1.2 266 224.0.0.0 240.0.0.0 On-link 127.0.0.1 306 224.0.0.0 240.0.0.0 On-link 192.168.1.2 266 255.255.255.255 255.255.255.255 On-link 127.0.0.1 306 255.255.255.255 255.255.255.255 On-link 192.168.1.2 266 =========================================================================== Persistent Routes: Network Address Netmask Gateway Address Metric 169.254.0.0 255.255.0.0 192.168.1.112 1 =========================================================================== IPv6 Route Table =========================================================================== Active Routes: If Metric Network Destination Gateway 13 58 ::/0 On-link 1 306 ::1/128 On-link 13 58 2001::/32 On-link 13 306 2001:0:4137:9e76:14ba:586:3f57:fefd/128 On-link 11 266 fe80::/64 On-link 13 306 fe80::/64 On-link 13 306 fe80::14ba:586:3f57:fefd/128 On-link 11 266 fe80::39d5:6cca:d2f6:8f40/128 On-link 1 306 ff00::/8 On-link 13 306 ff00::/8 On-link 11 266 ff00::/8 On-link =========================================================================== Persistent Routes: None

CinciKid, some questions: 1. Are you sure that a solid light is a good thing on your Willtel? On my box at home ( not a Wlltel) it is NOT a good thing. it should be blinking intermittenlty. 2. When the wirless client connects does it only cause a problem for other wireless clients or also for wired clinets. Does it ONLY occur when a new wireless client comes online or does it also happen when a new wired client comes online? 3. You say that this also occurred with the old wireless router. Were the answers to all of the questions in # 2 the same with the old wireless router? 4. When you say " the NetGear router doesn't appear to have assigned the IP address associated with the 169.254 router", what are referring to when you say the 169.254 router??? Troy

The DSL light (green LED) is solid. Cincinnati Bell says blinking/intermittent light is a sign of problems there. The Ethernet light on the Willtel is blinking, presumably in conjuction with ethernet traffic.

>2. When the wirless client connects does it only cause a problem for other wireless clients or also for wired clinets. >Does it ONLY occur when a new wireless client comes online or does it also happen when a new wired client comes online? Seems to affect mostly wireless clients, but it's not consistent. >3. You say that this also occurred with the old wireless router. Were the answers to all of the >questions in # 2 the same with the old wireless router? The issues were the same with the old wireless router. >4. When you say "the NetGear router doesn't appear to have assigned the IP address associated with the 169.254 router", >what are referring to when you say the 169.254 router??? Sorry, meant to say 169.254 network, when we look at the DHCP-assigned addresses on the netgear router, it shows a mix of wireless network and wired network IP address assignments. The Windows systems are identified by hostname, but there are two or three systems that provide no identification. None of these hosts have 192,168.1.12 as an assigned IP address, so it's as if some other box is on the network with a static IP address assignment. Not clear why it would advertise a route through it, though.

Cincikid, More questions Are the computers that are NOT identified by name showing 169.254 addresses in DHCP? If they are not showing 169.254 addresses, do any of these computers use the Alternate configuration feature. ( meaning they are set for DHCP but will use a statically assigned ip address if the DHCP server does not answer)? Also does the number of DHCP clients showing on the router match the number of machines? How many addreses are available to lease in the DHCP server on the router? Finally, does the DHCP server in the router have a setting for lease period and if so what is it set to? Troy

> 1. Are the computers that are NOT identified by name showing 169.254 addresses in DHCP? They are not, they are showing addresses assigned by the router, except for one machine that seems to persist at 192.168.1.12 > 2. If they are not showing 169.254 addresses, do any of these computers use the Alternate configuration feature. >(meaning they are set for DHCP but will use a statically assigned ip address if the DHCP server does not answer)? Not sure, will check. The Windows 7 systems behave as if they are getting the IP address assignment. The 169.254.0.0 address is used for ZeroConf (RFC 3927) for IP4, which is what BonJour uses. There are lots of discussion threads about Adobe CS3 installing an old version of Bonjour on Windows 7 systems, I'll verify those configurations next time I'm on-site to be sure. > 3. Also does the number of DHCP clients showing on the router match the number of machines? Not precisely, though it's under 10 machines. > 4. How many addresses are available to lease in the DHCP server on the router? 150 5. Finally, does the DHCP server in the router have a setting for lease period and if so what is it set to? 24 hour lease period

> 1. Are the computers that are NOT identified by name showing 169.254 addresses in DHCP? They are not, they are showing addresses assigned by the router, except for one machine that seems to persist at 192.168.1.12 > 2. If they are not showing 169.254 addresses, do any of these computers use the Alternate configuration feature. >(meaning they are set for DHCP but will use a statically assigned ip address if the DHCP server does not answer)? Not sure, will check. The Windows 7 systems behave as if they are getting the IP address assignment. The 169.254.0.0 address is used for ZeroConf (RFC 3927) for IP4, which is what BonJour uses. There are lots of discussion threads about Adobe CS3 installing an old version of Bonjour on Windows 7 systems, I'll verify those configurations next time I'm on-site to be sure. [Note: It seems likely that the WHS box from Acer is advertising itself via ZeroConf/Bonjour so other machines on the network can use its media features] > 3. Also does the number of DHCP clients showing on the router match the number of machines? Not precisely, though it's under 10 machines. > 4. How many addresses are available to lease in the DHCP server on the router? 150 5. Finally, does the DHCP server in the router have a setting for lease period and if so what is it set to? 24 hour lease period

The problem was finally identified as a failing piece of network hardware. We identified this by a process of elimination, disconnecting and reconnecting network hardware until the problems reoccurred. A 10/100 Ethernet hub that had been in use for a few years, had partially failed. It was showing an active port even when nothing was connected to it. Once the bad equipment was removed from the network, everything started working again. This was affecting both wired and wireless connections, even though that port was presumably isolated with a switch. In summary, we didn't have to change anything related to Windows 7 networking.