# `gnrc_ipv6_ext` test This test sends a packet to itself with extension headers. This is based on gnrc_networking example. Enable debug output of `gnrc_ipv6.c` before run. When the test is run, it should show the following debug output: ``` ipv6: Received (src = fd01::1, dst = fd01::2, next header = 0, length = 40) ipv6: forward nh = 0 to other threads ipv6: unable to forward packet as no one is interested in it ipv6: handle extension header (nh = 0) ipv6: forward nh = 43 to other threads ipv6: unable to forward packet as no one is interested in it ipv6: handle extension header (nh = 43) ipv6: waiting for incoming message. ipv6: GNRC_NETAPI_MSG_TYPE_RCV received ipv6: Received (src = fd01::1, dst = fd01::3, next header = 0, length = 40) ipv6: forward nh = 0 to other threads ipv6: unable to forward packet as no one is interested in it ipv6: handle extension header (nh = 0) ipv6: forward nh = 43 to other threads ipv6: unable to forward packet as no one is interested in it ipv6: handle extension header (nh = 43) ipv6: waiting for incoming message. ipv6: GNRC_NETAPI_MSG_TYPE_RCV received ipv6: Received (src = fd01::1, dst = fd01::2, next header = 0, length = 40) ipv6: forward nh = 0 to other threads ipv6: unable to forward packet as no one is interested in it ipv6: handle extension header (nh = 0) ipv6: forward nh = 43 to other threads ipv6: unable to forward packet as no one is interested in it ipv6: handle extension header (nh = 43) ipv6: forward nh = 17 to other threads ipv6: Send receive command for 0x1060b8 to 5 ipv6: waiting for incoming message. pkt->users: 0 ``` It configures the network interface with addresses fd01::02 and fd01::03. Then it sends a packet to fd01::02 with a routing extension header containing addresses fd01::03 and fd01::02. So the packet should be forwarded from fd01::02 to fd01::03, then to fd01::02 again. The packet has a Hop-by-Hop extension header that should be ignored. The test also asserts that the packet is released.