Hi, I have written a sample code to modify the link-local address of an Ethernet interface. The code snippet is - while(1) { printf("\n1.Add Link Local\n2.Modify LinkLocal\n"); scanf("%d", &ch); switch(ch) { case 1: { add_linklocaladdr(fd, NLM_F_CREATE|NLM_F_EXCL); break; } case 2: { add_linklocaladdr(fd, NLM_F_REPLACE); break; } ------------- ------------- void add_linklocaladdr(int fd, int flags)) { ------------- ------------- nlh = (struct nlmsghdr *)buf; len = MSG_ALIGN(sizeof(struct nlmsghdr)); nlh->nlmsg_len = len; nlh->nlmsg_type = RTM_NEWADDR; nlh->nlmsg_flags = NLM_F_REQUEST | flag; nlh->nlmsg_seq = 1; ifadr = nlmsg_put_extra_header(nlh, sizeof(struct ifaddrmsg)); ifadr->ifa_family = AF_INET6; ifadr->ifa_prefixlen = 0x40 ; /*hardcoded*/ ifadr->ifa_flags = IFA_F_PERMANENT;; ifadr->ifa_scope = RT_SCOPE_HOST; ifadr->ifa_index = 2; /*Push 'struct nlattr' */ attr_put(nlh, IFA_ADDRESS, dst); When I execute case 1 (add link-local), a new ipv6 ip is getting added. I want to modify an existing link local address in case2, but it's not working. Can anybody help me correcting this code for case2. Thanks & Regards Murali Annamneni ::DISCLAIMER:: ---------------------------------------------------------------------------------------------------------------------------------------------------- The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only. E-mail transmission is not guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or may contain viruses in transmission. The e mail and its contents (with or without referred errors) shall therefore not attach any liability on the originator or HCL or its affiliates. Views or opinions, if any, presented in this email are solely those of the author and may not necessarily reflect the views or opinions of HCL or its affiliates. Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of this message without the prior written consent of authorized representative of HCL is strictly prohibited. If you have received this email in error please delete it and notify the sender immediately. Before opening any email and/or attachments, please check them for viruses and other defects. ----------------------------------------------------------------------------------------------------------------------------------------------------