How to set a fixed path MTU in SCTP_PEER_ADDR_PARMS on an SCTP socket

Issue

• Unable to set a fixed path MTU in SCTP_PEER_ADDR_PARMS on an SCTP socket. The setsockopt() call does not return an error, but does not change the value either.
• Code used to try this:

struct sctp_paddrparams params;  
int len = sizeof(params);  

int s = socket(AF_INET,SOCK_STREAM,IPPROTO_SCTP);  

memset(&params, 0, sizeof(params));  

if (getsockopt(s,IPPROTO_SCTP,SCTP_PEER_ADDR_PARAMS, &params, &len)) {  
    perror("getsockopt");  
    exit(1);  
}  
params.spp_pathmtu = new_pathmtu;  
if (setsockopt(s,IPPROTO_SCTP,SCTP_PEER_ADDR_PARAMS, &params, len)) {
    perror("setsockopt");  
    exit(1); 
}