unicast to multicast conversion?

Hi, I have an important device residing outside my network (which is out of my control) that sends a UDP stream of data to a unicast address in my network. Problem is, there are multiple hosts in my network and neighbouring internal networks that are interested in this UDP stream. Multicast jumps to my mind in this scenario but problem is I have no control on the external device to have it send to a multicast address.

Is there a way that I can convert the unicast destination address to multicast address, and then have the hosts interested in the traffic as part of a multicast group? I have tried NAT to translate unicast to multicast, but doesn't seem to work.

TIA for any suggestions.

ip multicast routing

! interface FastEthernet1/1 no switchport ip address 10.100.1.254 255.255.255.0 ip nat inside ip virtual-reassembly no cdp enable ip pim dense-mode !

! interface FastEthernet1/4 no switchport ip address 10.100.254.1 255.255.255.252 ip nat outside ip virtual-reassembly no cdp enable ip pim dense-mode !

! interface FastEthernet1/5 no switchport ip address 10.100.254.5 255.255.255.252 ip nat outside ip virtual-reassembly no cdp enable ip pim dense-mode !

ip nat inside source static 10.100.1.9 233.0.0.1 -----> unidirectional UDP stream (src:192.168.14.120, dst:10.100.1.9) always travel from fa1/4 to fa1/1 ip nat inside source static 10.100.1.10 233.0.0.2 -----> unidirectional UDP stream (src:192.168.14.120, dst:10.100.1.10) always travel from fa1/5 to fa1/1. (note: same source address, but actually from a totally different network to which the first UDP stream originates)

ip nat outside source list 100 pool mypool ip nat pool mypool 193.168.14.120 193.168.14.120 netmask 255.255.255.0 ip access-list 100 permit ip host 192.168.14.120 host ----> this is to translate one of the UDP stream from src:192.168.14.120 to 193.168.14.120 to differentiate the source.

If flow goes from Fa1/4 -> Fa1/1 (s:192.168.14.120/d:10.100.1.9) you should do the following:

int fa1/4 ip nat inside

int fa1/1 ip nat outside

ip nat outside source static 233.0.0.1 10.100.1.9 extendable

For Fa1/5 -> Fa1/1 (s:192.168.14.120/d:10.100.1.10):

ip nat outside source static 233.0.0.2 10.100.1.10 extendable

Flows are different (S,G) pairs, so there's no really need to translate source ip address.

and, of course:

int fa1/5 ip nat inside

You can watch translations by using 'debug ip nat translation'. It is not recommended to do that if you have high volume traffic or many nat translations because it could burden the switch's cpu and add additional problems.

Regards,

Thanks Ivan. From your suggestion which uses static translations, it won't work for other flows.

I have: SNMP traps (UDP) from Fa1/4 -> Fa1/1 (s: 192.168.14.10/d:10.100.1.1) and SNMP traps (UDP) from Fa1/5 -> Fa1/1 (s: 192.168.14.10/d:10.100.1.1)

The reason I want to translate the source 192.168.14.10 to 193.168.14.10 is so that the SNMP traps are differentiated from the two identical source addresses.

Any suggestion to take this into account?