“show error”, “show ip fib”: rough guess: 70.1.1.58 hits a miss / drop adjacency.
From: vpp-dev-boun...@lists.fd.io [mailto:vpp-dev-boun...@lists.fd.io] On Behalf Of Prerit Jain Sent: Tuesday, November 22, 2016 7:48 AM To: vpp-dev@lists.fd.io Subject: Re: [vpp-dev] Fwd: Punting UDP packets to Kernel Hi, Thanks for the help. Now I am receiving the UDP punt packets in the UDP application running on Linux. However I am not able to send back the packets from UDP applications, the packets are getting dropped on VPP. Below is the trace - vpp> trace add tuntap-rx 10 00:02:49:998097: ip4-input-no-checksum UDP: 70.1.1.51 -> 70.1.1.58 tos 0x00, ttl 64, length 128, checksum 0x7596 fragment id 0x7668 UDP: 50000 -> 5000 length 108, checksum 0xec09 00:02:49:998098: ip4-drop UDP: 70.1.1.51 -> 70.1.1.58 tos 0x00, ttl 64, length 128, checksum 0x7596 fragment id 0x7668 UDP: 50000 -> 5000 length 108, checksum 0xec09 00:02:49:998099: error-drop ip4-input: ip4 adjacency drop I browsed the code of ip4_input_inline and found that next0 value is always filled as 5 in below function. #define vlib_validate_buffer_enqueue_x1(vm,node,next_index,to_next,n_left_to_next,bi0,next0) next0(5) means ip4_drop :- ip4-input-no-checksum error-drop [0] tuntap-rx error-punt [1] tapcli-rx ip4-lookup [2] dpdk-input ip4-lookup-multicast [3] handoff-dispatch ip4-icmp-error [4] ip4-drop [5] next0 variable is filled as 5 by the function vnet_get_config_data. Please let me know what is the purpose of net_get_config_data and how it determines the next node?? Regards Prerit On Fri, Nov 18, 2016 at 8:21 PM, John Lo (loj) <l...@cisco.com<mailto:l...@cisco.com>> wrote: The tuntap-tx node in VPP does not save any data to support packet trace. That’s why you do see any packet trace after error-punt. -John From: vpp-dev-boun...@lists.fd.io<mailto:vpp-dev-boun...@lists.fd.io> [mailto:vpp-dev-boun...@lists.fd.io<mailto:vpp-dev-boun...@lists.fd.io>] On Behalf Of Dave Barach (dbarach) Sent: Friday, November 18, 2016 8:23 AM To: Prerit Jain <prerit.j...@gmail.com<mailto:prerit.j...@gmail.com>> Cc: vpp-dev@lists.fd.io<mailto:vpp-dev@lists.fd.io> Subject: Re: [vpp-dev] Fwd: Punting UDP packets to Kernel You saw the packets w/ tcpdump, right? Thanks… Dave From: Prerit Jain [mailto:prerit.j...@gmail.com] Sent: Friday, November 18, 2016 8:15 AM To: Dave Barach (dbarach) <dbar...@cisco.com<mailto:dbar...@cisco.com>> Cc: vpp-dev@lists.fd.io<mailto:vpp-dev@lists.fd.io> Subject: Re: [vpp-dev] Fwd: Punting UDP packets to Kernel You mean that ip4-udp-punt node will directly write to tuntap interface for sending the packet to Kernel. On Fri, Nov 18, 2016 at 5:54 PM, Dave Barach (dbarach) <dbar...@cisco.com<mailto:dbar...@cisco.com>> wrote: Expected behavior. From: vpp-dev-boun...@lists.fd.io<mailto:vpp-dev-boun...@lists.fd.io> [mailto:vpp-dev-boun...@lists.fd.io<mailto:vpp-dev-boun...@lists.fd.io>] On Behalf Of Prerit Jain Sent: Friday, November 18, 2016 5:33 AM To: vpp-dev@lists.fd.io<mailto:vpp-dev@lists.fd.io> Subject: [vpp-dev] Fwd: Punting UDP packets to Kernel Thanks Dave. After adding below code in /etc/vpp/startup.conf tuntap { enable } I am able to capture the packets in kernel using tcpdump. However still the packet flow is terminating in error-punt in trace ... 00:06:52:855592: ip4-local UDP: 70.1.1.58 -> 70.1.1.51 tos 0x00, ttl 64, length 1028, checksum 0xcf79 fragment id 0x1901 UDP: 5000 -> 4500 length 1008, checksum 0x8d26 00:06:52:855592: ip4-udp-lookup UDP: src-port 5000 dst-port 4500 00:06:52:855593: error-punt ip4-udp-punt: udp port punt I do not see the node "tuntap-tx" in trace. While punting packet to kernel, the packet will not pass through "tuntap-tx" ?? On Thu, Nov 17, 2016 at 11:30 PM, Dave Barach (dbarach) <dbar...@cisco.com<mailto:dbar...@cisco.com>> wrote: See .../vnet/vnet/unix/tuntap.c vs. .../vnet/vnet/unix/tapcli.c. Only the tuntap device is capable of punting packets to the linux stack through a tun interface. You picked the wrong one. Note that tuntap must be enabled explicitly from the vpp command line. Thanks… Dave From: vpp-dev-boun...@lists.fd.io<mailto:vpp-dev-boun...@lists.fd.io> [mailto:vpp-dev-boun...@lists.fd.io<mailto:vpp-dev-boun...@lists.fd.io>] On Behalf Of Prerit Jain Sent: Thursday, November 17, 2016 7:08 AM To: vpp-dev@lists.fd.io<mailto:vpp-dev@lists.fd.io> Subject: [vpp-dev] Punting UDP packets to Kernel I want to send UDP packets with port 4500 to Kernel. For that I send UDP packets from external interface (70.1.1.58:port 5000) to VPP host (70.1.1.51<http://70.1.1.51>: 4500) and did below configuration. Set up the punt environment- set punt udp 4500 Created the tap interface - tap connect tap-0 In the below capture VPP trace, the packet are not going beyond the node (ip4-udp-punt) to kernel. 00:06:52:855590: dpdk-input GigabitEthernet1/0/2 rx queue 0 buffer 0x174fcf: current data 14, length 1028, free-list 0, totlen-nifb 0, trace 0x9 PKT MBUF: port 0, nb_segs 1, pkt_len 1042 buf_len 2176, data_len 1042, ol_flags 0x0, data_off 128, phys_addr 0xd753b2c0 packet_type 0x211 Packet Types RTE_PTYPE_L2_ETHER (0x0001) Ethernet packet RTE_PTYPE_L3_IPV4 (0x0010) IPv4 packet without extension headers RTE_PTYPE_L4_UDP (0x0200) UDP packet IP4: ec:f4:bb:d5:68:a6 -> ec:f4:bb:c4:4d:46 UDP: 70.1.1.58 -> 70.1.1.51 tos 0x00, ttl 64, length 1028, checksum 0xcf79 fragment id 0x1901 UDP: 5000 -> 4500 length 1008, checksum 0x8d26 00:06:52:855591: ip4-input-no-checksum UDP: 70.1.1.58 -> 70.1.1.51 tos 0x00, ttl 64, length 1028, checksum 0xcf79 fragment id 0x1901 UDP: 5000 -> 4500 length 1008, checksum 0x8d26 00:06:52:855592: ip4-lookup fib 0 dpo-idx 5 flow hash: 0x00000000 UDP: 70.1.1.58 -> 70.1.1.51 tos 0x00, ttl 64, length 1028, checksum 0xcf79 fragment id 0x1901 UDP: 5000 -> 4500 length 1008, checksum 0x8d26 00:06:52:855592: ip4-local UDP: 70.1.1.58 -> 70.1.1.51 tos 0x00, ttl 64, length 1028, checksum 0xcf79 fragment id 0x1901 UDP: 5000 -> 4500 length 1008, checksum 0x8d26 00:06:52:855592: ip4-udp-lookup UDP: src-port 5000 dst-port 4500 00:06:52:855593: error-punt ip4-udp-punt: udp port punt
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