TTL1 traffic Across Vlans

[Gr4cchus]

My main problem is getting a chromecast discoverable from another vlan. So I tried setting up smcroute with a multihomed vm. Im assuming smcroute cannot help with this cause the chromecast ttl traffic is set to 1?

mroute from ens160 group 224.0.0.0/4 to ens192
mroute from ens192 group 224.0.0.0/4 to ens160

Heard iptables can adjust ttl values but doesnt seem to change the outcome

Chain PREROUTING (policy ACCEPT 419K packets, 591M bytes)
 pkts bytes target     prot opt in     out     source               destination         
61723 7926K TTL        0    --  *      *       0.0.0.0/0            224.0.0.0/4          TTL set to 5

Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain OUTPUT (policy ACCEPT 147K packets, 8691K bytes)
 pkts bytes target     prot opt in     out     source               destination         
11566  373K TTL        0    --  *      *       0.0.0.0/0            224.0.0.0/4          TTL set to 64

Chain POSTROUTING (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Im assuming as soon as the ttl1 traffic hits the cisco nexus 3048 l3 switch in this case its stopped. What i dont understand tho is how others sound like they can get it to work using mdns repeaters like avahi or w.e. ubiquiti, vyos, pfsense, OPNsense use.

[troglobit]

For many services multicast, like mDNS-SD, is just for discovering the service. The next step is for the end device to actually connect and start a stream, which is usually done over unicast. So if you do not have routing set up between your different subnets (VLANs), then you are sort of out luck.

If it is mDNS that's being used by the Chromecast, then the reflector setup and unicast routing between your subnets would be my recommendation.

[Gr4cchus]

Normal traffic works between the networks/vlans if thats what you mean. pings, webservers, ssh etc. Ive configured PIM on this ospf l3 switch everything is connected to before, didnt seem to change much. PIM would of taken care of all that or unicast is something else to configure? Or some of this needs to be done on the smcroute server? Ive tried variations of things, its hard to keep track of every result.