What is a hardware firewall? Wi-Fi Facts Tips And Problem Solvers

If my router has one, do I need to run the Windows firewall or other third-party firewall software?

Wireless routers have a hardware firewall that safeguards the network by providing both incoming and outgoing protection. A hardware firewall will include network address translation (NAT) capabilities that make your PC invisible to anyone trying to attack it. If you enable the hardware firewall, you probably don't need a third-party software firewall. You should still run the Windows firewall, however, because it keeps a low profile and will stop basic worms if your PC gets hit by a drive-by downloader.

What should I do to secure my Wi-Fi network?

Routers offer two common forms of security: WEP, and Wi-Fi Protected Access (WPA) encryption. Both are easy to enable, although you'll get maximum protection from WPA. To activate security, go to your router's browser-based administration tool (the default address for most routers is http://192.168.0.1 or http://192.168.1.1) and look for the wireless-security area. WPA requires you to enter a simple security phrase (eight to 63 characters), or, with some routers, a more secure (but much harder to remember) 64-digit key. Similarly, WEP demands that you choose from 64-bit or 128-bit encryption, and enter an alphanumeric hex phrase,.

In addition to enabling wireless security, you can also disable the broadcasting of the Service Set Identifier (SSID, or network name). Doing so can make the network more difficult for hackers to see. Also, make sure to enable the router's hardware firewall (more on that later), and change the router's default password. And never enable file sharing, unless you really use it.

How To Get Secure Internet access in a public hotspot

Wireless transmissions on a public hot spot are typically unencrypted, and thus exposed to snooping. All computers on a public hot spot are typically exposed to each other, and thus vulnerable to network attacks.

Use a software firewall
A good software "firewall" will protect your computer from network attacks.

Make sure you are using strong passwords on all system accounts (including Administrator) and on all user accounts.

When Using Microsoft Windows

Use Simple File Sharing (Windows XP only); or
Make sure that all network shares are secured with strong passwords (all versions of Windows). Use Control Panel, Administrative Tools, Computer Management, Shared Folders, Shares to review and check Properties of all network shares

I Can't connect to wireless router or access point How Do I fix This

Most such wireless host devices have a web page that can be accessed with a standard web browser (e.g., Internet Explorer). Check the user manual for the address of the web page, and try to connect with a web browser.

If that doesn't work, try to ping the wireless host; under Microsoft Windows, click Start → Run,
type "%COMSPEC% /k ping WIRELESSHOSTADDRESS" and press [Enter].

If that doesn't work, check network addresses with Start → Run,
type "%COMSPEC% /k ipconfig /all" and press [Enter].

The wireless adapter network address will normally begin with the same three number groups as the wireless host web page; e.g., if the wireless host web page is 192.168.1.254, then the wireless adapter should be something like 192.168.1.11.

If you have a wireless router (not an access point), the Default Gateway should normally be the same network address as the wireless host web page.

If all else fails, you may need to reset the wireless host to factory default settings, and start over. Check the user manual for how to do this.

Wireless router locks up and has to be restarted How Do I Fix This

Possible causes:
Firmware bug Upgrade firmware to the latest version, downloaded from the manufacturer website. In some cases it may be necessary to ask Support for more current "beta" firmware.

Upgrade to a better/newer router
ARP cache/table overflow (typically in an older router)

Overwhelmed by peer-to-peer (P2P) filesharing application (e.g., BitTorrent/Azureus, eDonkey/eMule)

Reduce the maximum number of connections in the P2P application. Start pretty low and then work up to a maximum safe level.

My Wake On LAN (WOL) won't work from the Internet how Can I Fix This

The problem is that for a router to send magic WOL packets to your network, you need either: 1.an external router interface for generating and sending magic WOL packets, or 2.manual enabling of a static route or directed broadcast. Many (most?) low-end routers don't have that capability because of the risk of smurf denial of service attacks.
WHAT IS A SMURF ATTACK?

The smurf attack is a way of generating a lot of computer network traffic to a victim site. That is, it is a type of denial-of-service attack. Specifically, it floods a target system via spoofed broadcast ping messages.

In such an attack, a perpetrator sends a large amount of ICMP echo (ping) traffic to IP broadcast addresses, all of it having a spoofed source address of the intended victim. If the routing device delivering traffic to those broadcast addresses delivers the IP broadcast to all hosts (for example via a layer 2 broadcast), most hosts on that IP network will take the ICMP echo request and reply to it with an echo reply, multiplying the traffic by the number of hosts responding. On a multi-access broadcast network, hundreds of machines might reply to each packet.

Today, thanks largely to the ease with which administrators can make a network immune to this abuse, very few networks remain vulnerable to smurf attacks.

The fix is twofold:

Configure individual hosts and routers not to respond to ping requests to broadcast addresses, and Configure routers not to forward packets directed to broadcast addresses.

Another proposed solution, to fix this as well as other problems, is network ingress filtering which rejects the attacking packets on the basis of the forged source address.

Can't connect to Wi-Fi client bridge and Internet at the same time How Can I Fix This

In network terms, a bridge is transparent, passing data from each side to the other side (wireless to wired, wired to wireless). Thus in normal operation it doesn't have any use for IP addresses, just MAC addresses.

However, because of the need to manage Wi-Fi operation (SSID selection, WEP/WPA security, etc.), a Wi-Fi client bridge will typically have configuration screen(s) at a specified private IP address (e.g., 192.168.0.254) that can be accessed with a standard Web browser (e.g., Microsoft Internet Explorer) from a local computer. Unfortunately, unlike with a Wi-Fi router, a computer connected to a Wi-Fi client bridge can't normally communicate with both the client bridge configuration and the Internet at the same time.

How To Configure a Wi-Fi client bridge.

Problem: The NIC on a local computer needs a manually-assigned IP on the same subnet to connect to the client bridge config interface but then can't access the Internet, and when configured for DHCP through the client bridge can then talk to the Internet but not the client bridge.

Solutions:

Multihoming of the NIC (single link, multiple IP addresses)
For Microsoft Windows XP, see "Configuring Multiple IP Addresses on a Network Adapter" in Configuring IP Addressing and Name Resolution. Note: This only works with all manual addresses, not DHCP, which can be problematic when roaming unless managed with configuration manager software.

Two NICs in one computer, both connected to the client bridge:
one manually configured to talk to the client bridge config
the other with DHCP for the Internet.

Different computers for
client bridge config (manually configured)
Internet access (DHCP).

Connection manager software for rapid changing of NIC configuration profiles try theese.

Boingo Wi-Fi software (free)
Mobile Net Switch
NetSwitcher

PROBLEMS WHEN I ADDED WIRELESS ACESS TO A WIRED NETWORK

When adding wireless access to a wired network, as in the diagram, be careful not to create double NAT problems. Since the wired router already has NAT, use either:

1.a wireless access point with no NAT instead of a wireless router (with NAT), or
2.a wireless router setup as a wireless access point.