Base SSG configuration for MIRROR scheme
- Prepare the server according to the installation requirements.
- Install and configure the VEOS OS
- Set an IP address.
- Apply for license installation and fastDPI to Service Desk.
- After installing them, the following settings must be made in
etc/dpi/fastdpi.conf
:
Suppose the SCAT is connected as follows:
01-00.0, 01-00.1, 01-00.2
– receive the mirror traffic01-00.3
– connected to a router that receives and forwards responses to subscribers and to the internet.
To set the DPI in mirroring mode, you have to specify the following in the configuration:
In the configuration for the inbound ports in_dev
set the ports that accept mirror traffic:
in_dev=01-00.0:01-00.1:01-00.2
In the configuration for outgoing ports tap_dev
set the port to which the forwarding response is sent:
tap_dev=01-00.3
Specify the mode – asymmetric
asym_mode=1
Specify the direction of tap_dev
responses:
emit_direction=2 tap_mode=2
Specify that VLAN should be reset:
strip_tap_tags=1
Set MAC change:
replace_source_mac=00:25:90:E9:43:59 #- MAC address of card out_dev - dna0 replace_destination_mac=78:19:F7:0E:B1:F4 #- MAC address of the router, or the routing switch
Set the number of retries if there are network losses:
emit_duplication=3 #here, 3 is the number of repetitions (duplicates) of a packet with redirect or blocking.
Implementation scheme and description of operation
A TCP RST packet is sent to the restricted resource (IP2) to drop the connection. Blocking (HTTPS) and redirecting (HTTP) occurs because the SSG responds to the request from IP1 faster than IP2.
Header of the IP response packet
- Destination MAC – MAC address of the router port where the response link is connected.
- Source MAC – MAC address of the
out_dev
card. - Source IP – IP address of the restricted resource IP2.
- Destination IP – IP address of user IP1.
Router configuration example
The port on the router where the reply link from the SSG is included should be configured as a normal L3 port. The task is to receive a packet from the SSG and forward it to the subscriber based on the common routing tables.
Configuration example:
eth1
is connected to the Juniper MX side
#Settings on tha MX side: description from_SSG_redirect; unit 0 { family inet { address a.b.c.d/30; } }
Statistics collection
#FullNetflow/IPFIX netflow=8 netflow_full_collector_type=2 netflow_dev=eth3 netflow_timeout=20 netflow_full_collector=172.18.254.124:1500 netflow_rate_limit=30 netflow_passive_timeout=40 netflow_active_timeout=120 #ClickStream/IPFIX ipfix_dev=eth3 ipfix_tcp_collectors=172.18.254.124:1501 #SIP ipfix_meta_tcp_collectors=172.18.254.124:1511 rlimit_fsize=32000000000
Further settings are made depending on which components are to be used. The settings are described in the SSG components section.