IP multicast is a means of getting IP traffic from one host to a set of hosts without using broadcasting; that is, instead of every host getting the traffic, only those that want it will get it, without each having to maintain a separate connection to the server. IP unicast is where one host talks to another, multicast is where one host talks to a set of hosts, and broadcast is where one host talks to all hosts.

IP multicast packets are encapsulated for transmission through tunnels, so that they look like normal unicast datagrams to intervening routers and subnets. A multicast router that wants to send a multicast packet across a tunnel will prepend another IP header, set the destination address in the new header to be the unicast address of the multicast router at the other end of the tunnel, and set the IP protocol field in the new header to be 4 (which means the next protocol is IP).

IP-Multicast works by enabling network systems to join a multicast group that is identified by a multicast address. Multicast addresses are in the range of 224.0.0.0 to 239.255.255.255. Vypress Messenger and Vypress Auvis can join to an unlimited number of multicast groups. For example, when a desktop user joins the address, 225.100.100.100, all of the messages sent to that address from any other system will be received.

In eCopy ShareScan OP version 1.0, the Multicast IP information is hard-coded and cannot be changed. In eCopy ShareScan OP 1.1, there are alternative methods to discover MEAP-enabled devices. See the FAQ for discovering MEAP-enabled devices.

IP Multicast is an extension of the Internet Protocol, the protocol that make the Internet work. It supports multicast at a low-level protocol and is, in theory, more efficient than End-host Multicast. However, IP Multicast is not widely available. In fact, the original version of Jungle Monkey used IP Multicast, but we abondoned it because we couldn't find any users who had it.

The IP multicast software is available by anonymous FTP from the vmtp-ip directory on host gregorio.stanford.edu. Here's a snapshot of the files: ipmulti-pmax31c.tar ipmulti-sunos41x.tar.Z Binaries & patches for SunOS 4.1.1,2,3 ipmulticast-ultrix4.1.patch ipmulticast-ultrix4.2a-binary.tar ipmulticast-ultrix4.2a.patch ipmulticast.README [** Warning: out of date **] ipmulticast.tar.Z Sources for BSD You don't need kernel sources to add multicast support.

As soon as I try to log on or change aMSN's language, it crashes with the following message: X Error of failed request: BadValue (integer parameter out of range for operation), Major opcode of failed request: 45 (X_OpenFont) I try to run aMSN and it gives this error: Error in startup script: time value too large/small to represent while executing [...] procedure "ConvertLocalToUTC".

SSL is a protocol that allows secure connections across the Internet. Typically, SSL is used to protect HTTP traffic. However, other protocols (such as telnet) can run atop SSL. Enabling SSL through your firewall can be done the same way that you would allow HTTP traffic, if it's HTTP that you're using SSL to secure, which is usually true. The only difference is that instead of using something that will simply relay HTTP, you'll need something that can tunnel SSL.

Some organizations want to hide DNS names from the outside. Many experts don't think hiding DNS names is worthwhile, but if site/corporate policy mandates hiding domain names, this is one approach that is known to work. Another reason you may have to hide domain names is if you have a non-standard addressing scheme on your internal network. In that case, you have no choice but to hide those addresses.

Generally, making FTP work through the firewall is done either using a proxy server such as the firewall toolkit's ftp-gw or by permitting incoming connections to the network at a restricted port range, and otherwise restricting incoming connections using something like ''established'' screening rules. The FTP client is then modified to bind the data port to a port within that range. This entails being able to modify the FTP client application on internal hosts.

Telnet is generally supported either by using an application proxy such as the firewall toolkit's tn-gw, or by simply configuring a router to permit outgoing connections using something like the ''established'' screening rules. Application proxies could be in the form of a standalone proxy running on the bastion host, or in the form of a SOCKS server and a modified client.

RealNetworks maintains some information about how to get RealAudio working through your firewall7. It would be unwise to make any changes to your firewall without understanding what the changes will do, exactly, and knowing what risks the new changes will bring with them.

Yes! Some schools, libraries, cyber cafés, and work places block access to many websites. Hide My IP allows you to "tunnel" right through the network firewall you are behind so you can access any website that you have been blocked from.

Multicast is an alternative way of delivering video and radio channels at a much higher quality. It's a smarter way of serving large numbers of people. This means more live channels will be available for popular events like the Olympics.

Answer: You have multiple approaches for delivering IP telephony while keeping the firewall intact. The solution operates outside of the firewall and can utilize a Network Address Translation device (NAT) that only allows voice calls to the specific IP addresses through the firewall.

Yes. A port needs to be open through the firewall of course, and that port can be specified in the Client configuration.

Sort of. There is basic provision for a simple web proxy, which will allow you to query the Gnutella and hotline search engines, but most firewalls will not allow gnutella, hotline or OpenNapster connections. Enable the following ports for best results. Carracho downloads are not possible, only searching. I will add it if someone figures out the download protocol!