You are here: Home » Reply

Reply To: Share through WAN port?

#11147

rpedde
Participant

@dantidote wrote:

Heres a tricky one:
The server is all set up and it works just fine. I just found out that I’m not broadcasting to the whole building because there are 5 different subnets, and apparently i can only see and share to my subnet. I talked with the network engineer and this was what he said:

Dan,
Our Resnet network consists of the following subnets.
ID Subnet IP Address Mask Router
71 resnet-wads-g1 141.219.224.0 23 M160
72 resnet-wads-2 141.219.226.0 23 M160
73 resnet-wads-3 141.219.228.0 23 M160
74 resnet-wads-4 141.219.230.0 23 M160
75 resnet-wads-5 141.219.232.0 23 M160
76 resnet-wmcnair 141.219.234.0 23 M160
77 resnet-emcnair 141.219.76.0 22 M160
78 resnet-dhh 141.219.236.0 22 M160
79 resnet-heights 141.219.80.0 22 M160

A ‘broadcast’ or SMB share should work only within the local subnet.

Generally multicast will work across any of these subnets. IF the
application sets the TTL short, or a group for local it may not traverse
the network beyond a local subnet.

Can I somehow share to the whole building even though we’re all on different subnets?

It’s the second one — it’s a local multicast address. From the RFC:

The range of addresses between 224.0.0.0 and 224.0.0.255, inclusive,
is reserved for the use of routing protocols and other low-level
topology discovery or maintenance protocols, such as gateway discovery
and group membership reporting. Multicast routers should not forward
any multicast datagram with destination addresses in this range,
regardless of its TTL.

mDNS uses 224.0.0.251, so that’s the issue. You can’t really get around that without switch reconfiguration, so the netsec guy is telling you that you are SOL.