Multi-Tech Systems RF600 Manuel D’Utilisation

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Appendix A – Disposition of Events  
Multi-Tech Systems, Inc. RouteFinderVPN RF760/660/600VPN User Guide (PN S000323D) 
144 
 
Inbound Access (DNAT with Connection Tracking) 
 
Figure 3 
 Inbound Access (DNAT with Connection Tracking) 
Description of Figure 3 
The Access request originated from the source (204.26.122.9) to the destination (204.54.39.103), which is further 
DNATTED to the ip-address 192.168.1.76 on port 20:21.  
The above figure illustrates a capture of the FTP service.  
• 
Slno 1, in the above snapshot corresponds to the control connection (Remarks in the second half of the snapshot 
is a continuation of the capture). 
Remarks: 
Inbound Accepted
 
DNAT ip:port = 192.168.1.76:20:21
” 
Src: 204.26.122.9, Dst: 202.54.39.103, DNATTED to 192.168.1.76 on Port 20:21. 
• 
Slno 2, corresponds to a PASV Data connection. (Src:204.26.122.9, destined to 202.54.39.103, which in turn is 
DNATTED to 192.168.1.76 on port 62191). 
Remarks: 
Inbound Accepted
  
[SRC=204.26.122.9:DST=202.54.39.103:SPORT=41216:DPORT=21]
        
Dnat ip:port = 192.168.1.76:21
” 
o
 
Inbound Accepted – 
Inbound Log 
o
 
[SRC=204.26.122.9:DST=202.54.39.103:SPORT=41216:DPORT=21]
 – This corresponds to the 
CONTROL connection information” for this data connection. 
o
 
Dnat ip:port = 192.168.1.76:21
” – This corresponds to the “CONTROL connection’s DNATTED 
ipaddress” for this data connection. 
• 
Slno 3, corresponds to the ACTIVE Data connection originated from 192.168.1.76 (on SRC-PORT 20), which is 
masqueraded to a SRC:202.54.39.103 at the WAN interface of the candidate firewall, destined to 204.26.122.9. 
Remarks: 
Inbound Accepted
  
[SRC=204.26.122.9:DST=202.54.39.103:SPORT=41216:DPORT=21]
        
Dnat ip:port = 192.168.1.76:21
” 
o
 
Inbound Accepted – 
Inbound Log 
o
 
[SRC=204.26.122.9:DST=202.54.39.103:SPORT=41216:DPORT=21]
 – This corresponds to the 
CONTROL connection information” for this data connection. 
o
 
Dnat ip:port = 192.168.1.76:21
” – This corresponds to the “CONTROL connection’s DNATTED 
ipaddress” for this data connection.