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People fear what they do not understand. I know this is pure conjecture with regards to this particular situation, but I already had couple of clashes with ope

People fear what they do not understand. I know this is pure conjecture with regards to this particular situation, but I already had couple of clashes with operations people over use of multicast in my applications. They basically trying to tell me there is never valid case for multicast so they just outright filter it out everywhere with no possibility of enabling it.

tatersolid 5y ago
Multicast is semi-broken on most networks, and devolves into pure broadcast on the current LAN or VLAN in most cases. This in turn causes chatter havoc on LANs with many devices, such as corporate WiFi. Oh, and multicast is totally insecure unless you layer your own authentication and encryption on top. Multicast has been a dream since the 1990s but has been a nightmare in practice.
- lmilcin 5y ago
  I am talking about multicast for having applications talk to each other in a datacenter, not to have that traffic exposed to office clients. I understand most office networks are broken and if I send multicast I would just be causing untold mayhem. I have already resigned myself to the fact that the only way to have reliable communication with a client is to use HTTP. But in a DC where you control all your networking devices, configuration and people who maintain it, it should be possible to find a configuration that works reliably and allows devices to talk to each other without too much hassle.
  - tatersolid 5y ago
    > it should be possible to find a configuration that works reliably and allows devices to talk to each other without too much hassle. The number of multicast bugs in Cisco/Juniper/whatever enterprise gear is astonishing. It’s basically a DoS waiting to happen. And if you have multiple network vendors in your shop as all real networks do… forget it. As I said, my long experience is that multicast just doesn’t work reliably in practice except maybe for small layer-2-only networks. The same places where broadcast storms aren’t noticeable. Unicast with source replication is fast, cheap, and reliable.
- iso1210 5y ago
  Every network I have uses multicast just fine. And saying "multicast is totally insecure" is like saying "IP is totally insecure", it's just nonsense.

tatersolid 5y ago

Multicast is semi-broken on most networks, and devolves into pure broadcast on the current LAN or VLAN in most cases. This in turn causes chatter havoc on LANs with many devices, such as corporate WiFi. Oh, and multicast is totally insecure unless you layer your own authentication and encryption on top. Multicast has been a dream since the 1990s but has been a nightmare in practice.

lmilcin 5y ago
I am talking about multicast for having applications talk to each other in a datacenter, not to have that traffic exposed to office clients. I understand most office networks are broken and if I send multicast I would just be causing untold mayhem. I have already resigned myself to the fact that the only way to have reliable communication with a client is to use HTTP. But in a DC where you control all your networking devices, configuration and people who maintain it, it should be possible to find a configuration that works reliably and allows devices to talk to each other without too much hassle.
- tatersolid 5y ago
  > it should be possible to find a configuration that works reliably and allows devices to talk to each other without too much hassle. The number of multicast bugs in Cisco/Juniper/whatever enterprise gear is astonishing. It’s basically a DoS waiting to happen. And if you have multiple network vendors in your shop as all real networks do… forget it. As I said, my long experience is that multicast just doesn’t work reliably in practice except maybe for small layer-2-only networks. The same places where broadcast storms aren’t noticeable. Unicast with source replication is fast, cheap, and reliable.
iso1210 5y ago
Every network I have uses multicast just fine. And saying "multicast is totally insecure" is like saying "IP is totally insecure", it's just nonsense.