jepop - pops Juniper Ethernet headers from a .pcap file

Usage

usage: jepop [-h] [--overwrite] [--dmac DMAC] [--smac SMAC] [--vlans VLANS] inpcap outpcap

Packets captured on wan interfaces contain hostpath packets
Hostpath packets contain an additional Juniper Ethernet header which is not understood outside of Juniper products
This limits the ability to use these .pcap files with tools such as tcpreplay, ngrep, tcpflow and more
This utility reads packets from a .pcap file, pops the Juniper Ethernet header if found, then writes the packets to a new .pcap
It uses scapy (https://scapy.net) to achieve this
Hostbound packets (input direction) may have L2 headers stripped by the PFE, in this case a crafted Ethernet header is added
By default the crafted Ethernet header src and dst macs will be all zeros, you can specify macs with the smac and dmac options
Additionally, you can specify add up to 2 vlan tags to be added with the vlans option

• Reads packets from inpcap into a PacketList
• Each packet is checked for the presence of the Juniper Ethernet header
  -- If found, the l2_header_presence bit is used to determine if the payload is L2
  -- If L2, Juniper Ethernet header is popped and packet is appended to the output PacketList
  -- If not L2, the payload_type field is used to determine the L3 payload
  -- A new packet is created with a crafted Ethernet header, any vlans specified, and the L3 payload
  -- Packet is appended to output PacketList
• Output PacketList is written to outpcap

OPTIONAL ARGUMENTS

smac - source mac to be added to crafted L2 header
dmac - destination mac to be added to crafted L2 header
vlans - dot1q vlans to be added after crafted L2 header
overwrite - allows output file to be overwritten

LICENSE

GPL-2.0

CONTRIBUTORS

Juniper Networks is actively contributing to and maintaining this repo
Please contact jnpr-community-netdev@juniper.net for any queries

Contributors:

Chris Jenn