====== Network Interaction ======
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<accordion-item title="1. Is STP processed transparently?">
Yes.
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<accordion-item title="2. Can SSG support a configuration with a single 10G network interface in the server, where traffic passes through SSG using two VLANs (in and out)?">
No. This is not planned for future support.
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<accordion-item title="3. Can SSG set up a BGP link with a border router for exporting prefixes that need to be routed through SSG?">
Yes, this is possible. [[en:dpi:dpi_brief:install_point_ssg|More about router settings.]]
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<accordion-item title="4. If during a test connection to the internal LAN the 'ping' time hasn't changed, should there be a delay?">
The delay on the device, if the hardware meets our recommendations, does not exceed 30 µs (microseconds) or 0.03 ms (milliseconds). 'Ping' measurements start at 1 ms. Measuring such delays requires special software and equipment; in our lab, we use counters in nanoseconds supported by modern network cards.
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<accordion-item title="5. If implementing mirroring, can SSG remove tags on the output (out_dev=dnaX) when traffic with different tags comes on in_dev=dna1:dna2?">
SSG will send a response with the original packet tag if VLAN [[en:dpi:dpi_components:platform:dpi_vlan_recode|translation settings]] have not been applied.
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<accordion-item title="6. What is SSG? Is it a router, NAT, transparent proxy, or is it transparent to network devices?">
SSG is a DPI device, similar to Cisco SCE. It operates as a bridge, without IP addressing, and is invisible on the network.\\
The delay when using it is no more than 30 microseconds (based on tests, 16 µs), which is virtually indistinguishable from a direct connection.\\
[[en:dpi:dpi_brief:install_point_ssg|See detailed connection diagrams for SSG]].
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<accordion-item title="7. In what form is aggregated traffic provided? Are ports grouped through LACP?">
Yes, you can use LACP and LAG for traffic aggregation.\\
[[en:dpi:dpi_brief:install_point_ssg|See detailed connection diagrams for SSG]].
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<accordion-item title="8. At which point should the system connect, before or after termination on BRAS (in other words, at L2 or L3)?">
It depends on the task: if the platform connects as a DPI, then after the termination point; if BRAS, NAT functionality is required, then the SSG platform performs traffic termination directly.\\
[[en:dpi:dpi_brief:install_point_ssg|Connection diagrams]].
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<accordion-item title="9. How to optimize the WEB server network stack?">
Apply the following settings in the ''/etc/sysctl.conf'' file:
<code bash>
net.core.netdev_max_backlog=10000
net.core.somaxconn=262144
net.ipv4.tcp_syncookies=1
net.ipv4.tcp_max_syn_backlog = 262144
net.ipv4.tcp_max_tw_buckets = 720000
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_fin_timeout = 30
net.ipv4.tcp_keepalive_time = 1800
net.ipv4.tcp_keepalive_probes = 7
net.ipv4.tcp_keepalive_intvl = 30
net.core.wmem_max = 33554432
net.core.rmem_max = 33554432
net.core.rmem_default = 8388608
net.core.wmem_default = 4194394
net.ipv4.tcp_rmem = 4096 8388608 16777216
net.ipv4.tcp_wmem = 4096 4194394 16777216
</code>
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<accordion-item title="10. Why does one BGP session come up while another does not?">
Example:
  * Check ''tcpdump''. On the client's interface, mtu = 9000. \\
  * On one session, mss = 1480 during sync, while on the other, mss = 8500.\\ This indicates that one peer has a standard mtu of 1500, while the other has an increased mtu. \\
  * On sessions where mss is higher than 1480 and there is an IP header, set the settings in MX:
<code bash>neighbor 95.167.18.57 {
traceoptions {                      
file as12389.log size 1m files 3;
}
 description "-= RT AS12389 Upload =-";
 import [ bogus-reject MM-IN ];
 export REJECT-ALL;
  peer-as 12389;
  tcp-mss 1460;
}
 tcp-mss 1460;</code>

[[en:dpi:faq:fastdpi:ssg_platform|Administration questions]] 
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