Hello, i have atempted to configure tunnel interface for 6in4 protocol but so far i am not able to ping ipv6 server ip address. here below snippet of my Cisco router config; Tunnel ID T160425 ipv6 unicast-routing ipv6 cef ! interface Tunnel0 description SIXXS_frmrs01 no ip address ip mtu 1280 ipv6 address 2A01:240:FE00:2D8::2/64 ipv6 enable ipv6 verify unicast reverse-path ipv6 traffic-filter V6-FILTER in tunnel source Dialer0 tunnel mode ipv6ip tunnel destination 78.153.240.201 end ! interface Dialer0 ip address negotiated ip nat outside ip virtual-reassembly in encapsulation ppp dialer pool 1 dialer-group 1 no fair-queue ppp authentication chap pap callin ppp chap hostname XXXXX ppp chap password YYYYYY ppp pap sent-username XXXXX password YYYYY ppp ipcp dns request ! dialer-list 1 protocol ip permit dialer-list 1 protocol ipv6 permit ipv6 route ::/0 Tunnel0 ipv6 access-list V6-FILTER permit icmp any any permit ipv6 any any ! -----tests---- RTRFWLAN#ping ipv6 2A01:240:FE00:2D8::1 source tunnel 0 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 2A01:240:FE00:2D8::1, timeout is 2 seconds: Packet sent with a source address of 2A01:240:FE00:2D8::2 ..... Success rate is 0 percent (0/5) ----- show commands----- Tunnel0 is up, line protocol is up Hardware is Tunnel Description: SIXXS_frmrs01 MTU 17920 bytes, BW 100 Kbit/sec, DLY 50000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation TUNNEL, loopback not set Keepalive not set Tunnel source 62.62.Y.Y (Dialer0), destination 78.153.240.201 Tunnel Subblocks: src-track: Tunnel0 source tracking subblock associated with Dialer0 Set of tunnels with source Dialer0, 1 member (includes iterators), on interface <OK> Tunnel protocol/transport IPv6/IP Tunnel TTL 255 Tunnel transport MTU 1480 bytes Tunnel transmit bandwidth 8000 (kbps) Tunnel receive bandwidth 8000 (kbps) Last input 00:00:46, output 00:00:46, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/0 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 1110 packets input, 1186590 bytes, 0 no buffer Received 0 broadcasts (0 IP multicasts) 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 1186 packets output, 1168726 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 unknown protocol drops 0 output buffer failures, 0 output buffers swapped out ! RTRFWLAN#SHOW IPV6 interface tunnel 0 Tunnel0 is up, line protocol is up IPv6 is enabled, link-local address is FE80::3E3E:EC6E No Virtual link-local address(es): Description: SIXXS_frmrs01 Global unicast address(es): 2A01:240:FE00:2D8::2, subnet is 2A01:240:FE00:2D8::/64 Joined group address(es): FF02::1 FF02::2 FF02::1:FF00:2 FF02::1:FF3E:EC6E MTU is 1480 bytes ICMP error messages limited to one every 100 milliseconds ICMP redirects are enabled ICMP unreachables are sent Input features: Access List Verify Unicast Reverse-Path Inbound access list V6-FILTER IPv6 verify source reachable-via rx, allow default 0 verification drop(s) (process), 0 (CEF) 0 suppressed verification drop(s) (process), 0 (CEF) ND DAD is enabled, number of DAD attempts: 1 ND reachable time is 30000 milliseconds (using 30000) ND RAs are suppressed (periodic) Hosts use stateless autoconfig for addresses.