multicast foolishness
Posted: Sat Mar 16, 2013 8:47 am
I'm putting in a simple two position Telex CSoft replacement for a 1990 CC2+ system. Pretty straight forward. Five base stations per site, four sites, plus SIP phones at dispatch. They kept their T1 microwave links to each site. So, everything is staying at dispatch. Essentially, a Telex CEB replacing a MOT CEB. No great mysteries. Works perfectly.
The hard part is the two laptop remote dispatch requirement. ie: two Panasonic Toughbooks so they can dispatch from an EOC, or their kitchen table in their jammies, through the Intertubes. It's not my first time at the rodeo. I've done it before. But, it is always like pulling teeth. I always have to beat it into submission with blunt objects, stone knives, and bear claws. This time was no different. And it is because of multicast. I wish I understood this better.
I've used Cisco VPN, and Juniper VPN. Royal pains to make work, and I've had to hire it out to "experts" to build a working tunnel config. This time I decided to use what Telex recommends - DCB product. It's an appliance intended for techs like me with little expertise in layer 2 / layer 3 devices. Supposedly almost plug and play. Punch in the addressing and passwords, and away it goes! Not.
If I configure the server and client as described in their docs, I have ip connectivity but not udp on the Toughbooks running Win7Pro. I can ping. I can web into the Telex boxes to look at their configs. I can web into the DCB box to work on it's config. But! No multicast packets pass. CSoft and Telex System Manager just stare at you. No audio. No tx/rx. They are stones.
On the other hand, if I enable DHCP in the client virtual adapter (the DCB client creates a virtual network adapter with a static ip you assign), and have DHCP disabled in the server (the default), Windows gives the client adapter a stateless address (169.254.x.x). Multicast works. Tx/rx good. But! No ip. No ping. No http. You can't get to the boxes except through System Manager which works from the multicast level. Very odd.
Of course Telex says "Not our box - talk to DCB", and DCB says "Never heard of that before. Your configs are wrong. Check your configs." That was helpful guys. Great idea - check my configs. Why didn't I think of that? Holy Cow. Here I am again, and this time I'm using something that no one is expert at so I can't farm it out. I gotta figure it out on my own.
I rub two brain cells together hoping for some heat, and all I get is it seems like DCB or Windows were doing packet filtering. The DCB box has some Advanced / Tunnel / Filter settings, and they all say "filters disabled". Fine. Let's enable them. You get three choices - pass packets, drop packets, and filter disabled. Let's choose pass packets. Save. Reboot. Wait. Whoa! Holy Cow - it's working on this laptop. It's working on the other laptop. Yippie! Let's put it back to the defaults of filters disabled and see what happens - it's broken again - Yea! Let's pass packets again - Yea! It's working. Leave it alone.
Hello DCB - how come? "I hate to disagree with a customer, but that's impossible. Check your configs." Okay. Check what? (crickets)
I'll take a win anyway I can. I'm not proud. The two Toughbook laptops work. All functions good. Who cares if the product manual is wrong. It's not the first time that's happened to me. Let's set up my company Win7 Acer laptop so I can support their system remotely. And guess what? It doesn't work. Here we go again with a static ip with ip connectivity but no udp, or a stateless address with udp but no ip.
Toggle all the server filters back to disabled, and now the Acer still doesn't work, but the Panasonics do. Wait a minute. Restart all three machines. None of them work now. Windows in the Toughbooks remembered something about getting to the server. Rebooting the PC's killed that. Toggle the filters again. Panasonics work. Acer still a stone until I give it a stateless addy.
Enable DHCP in the server on the trusted side. Enable DHCP in the Acer virtual adapter. It gets an addy in the correct range ... and ... it works. IP and udp. CSoft walks and talks. System Manager finds all the devices, but I get timeout errors when I try to read them. I can web into them, but I cannot fetch their configs in SM. Kill CSoft. Now SM can't see anything. No devices to be found. I can ping them. I can web in. But, System Manager says "nope, sorry, nobody there". Fire up CSoft. "Oh wait! My bad - there are lots of Telex devices now. Watch me load up the screen". Kill CSoft. SM goes dark again.
I had to put it down. That is enough foolishness for today. I have to have different configurations for different PC's running slightly different versions of Windows? And the configurations don't follow the simple rules of an appliance as the OEM promised? Oy ve.
The hard part is the two laptop remote dispatch requirement. ie: two Panasonic Toughbooks so they can dispatch from an EOC, or their kitchen table in their jammies, through the Intertubes. It's not my first time at the rodeo. I've done it before. But, it is always like pulling teeth. I always have to beat it into submission with blunt objects, stone knives, and bear claws. This time was no different. And it is because of multicast. I wish I understood this better.
I've used Cisco VPN, and Juniper VPN. Royal pains to make work, and I've had to hire it out to "experts" to build a working tunnel config. This time I decided to use what Telex recommends - DCB product. It's an appliance intended for techs like me with little expertise in layer 2 / layer 3 devices. Supposedly almost plug and play. Punch in the addressing and passwords, and away it goes! Not.
If I configure the server and client as described in their docs, I have ip connectivity but not udp on the Toughbooks running Win7Pro. I can ping. I can web into the Telex boxes to look at their configs. I can web into the DCB box to work on it's config. But! No multicast packets pass. CSoft and Telex System Manager just stare at you. No audio. No tx/rx. They are stones.
On the other hand, if I enable DHCP in the client virtual adapter (the DCB client creates a virtual network adapter with a static ip you assign), and have DHCP disabled in the server (the default), Windows gives the client adapter a stateless address (169.254.x.x). Multicast works. Tx/rx good. But! No ip. No ping. No http. You can't get to the boxes except through System Manager which works from the multicast level. Very odd.
Of course Telex says "Not our box - talk to DCB", and DCB says "Never heard of that before. Your configs are wrong. Check your configs." That was helpful guys. Great idea - check my configs. Why didn't I think of that? Holy Cow. Here I am again, and this time I'm using something that no one is expert at so I can't farm it out. I gotta figure it out on my own.
I rub two brain cells together hoping for some heat, and all I get is it seems like DCB or Windows were doing packet filtering. The DCB box has some Advanced / Tunnel / Filter settings, and they all say "filters disabled". Fine. Let's enable them. You get three choices - pass packets, drop packets, and filter disabled. Let's choose pass packets. Save. Reboot. Wait. Whoa! Holy Cow - it's working on this laptop. It's working on the other laptop. Yippie! Let's put it back to the defaults of filters disabled and see what happens - it's broken again - Yea! Let's pass packets again - Yea! It's working. Leave it alone.
Hello DCB - how come? "I hate to disagree with a customer, but that's impossible. Check your configs." Okay. Check what? (crickets)
I'll take a win anyway I can. I'm not proud. The two Toughbook laptops work. All functions good. Who cares if the product manual is wrong. It's not the first time that's happened to me. Let's set up my company Win7 Acer laptop so I can support their system remotely. And guess what? It doesn't work. Here we go again with a static ip with ip connectivity but no udp, or a stateless address with udp but no ip.
Toggle all the server filters back to disabled, and now the Acer still doesn't work, but the Panasonics do. Wait a minute. Restart all three machines. None of them work now. Windows in the Toughbooks remembered something about getting to the server. Rebooting the PC's killed that. Toggle the filters again. Panasonics work. Acer still a stone until I give it a stateless addy.
Enable DHCP in the server on the trusted side. Enable DHCP in the Acer virtual adapter. It gets an addy in the correct range ... and ... it works. IP and udp. CSoft walks and talks. System Manager finds all the devices, but I get timeout errors when I try to read them. I can web into them, but I cannot fetch their configs in SM. Kill CSoft. Now SM can't see anything. No devices to be found. I can ping them. I can web in. But, System Manager says "nope, sorry, nobody there". Fire up CSoft. "Oh wait! My bad - there are lots of Telex devices now. Watch me load up the screen". Kill CSoft. SM goes dark again.
I had to put it down. That is enough foolishness for today. I have to have different configurations for different PC's running slightly different versions of Windows? And the configurations don't follow the simple rules of an appliance as the OEM promised? Oy ve.