nat

问题 I deal with design of peer to peer communication between mobile unit and user phone. Mobile unit is targeted into cars, so it is possible that it could be connected to many various ISPs. It can be also expected that the clients will be often disconnects. I need to find best solution in NAT traversal techniques, which is applicable in conditions of mobile network, which are little different than the usual networks as WiFi. I search for often used techniques and found a many different practices

问题 My host OS is Windows . I use Vagrant with box ubuntu/trusty64 Yesterday, after the host PC was rebooted, I am experiencing a problem - port collision, when using vagrant up or vagrant reload . I already updated vagrant to latest version, deleted all settings, all machines, created all from blank (without reinstalling OS on host machine) And the problem still persists. Whe I use port_forward, from 80 to port I want (lets call it port X ) - I get an error - port collision on port X . It can be

问题 I have a UDP server running on my private network.I have a device which is beyond NAT which sends UDP packets to my server through public IP. I am able to receive the UDP packets, parse them and I can view the pay load, src and dest port. Now I need to send an ACK message to that device so I have captured the ip and port numbers and sending a UDP packet to it. But I could not able to view any UDP packets in that device. My question is as my Device is beyond NAT the IP address and port number

问题 I'm building a network appliance. I need to support NAT and IP packet fragmentation. When I change the source or destination address of a UDP packet, I have to correct the UDP checksum (and the IP checksum too, but that's trivial). When the packet is fragmented, I'd have to collect all the fragments to recalculate the checksum. I know the old address and the new address. I'd like to: Un-negate the checksum Subtract the old address Add the new address Re-reduce the sum and negate This process

问题 My need is to communicate between 2 client behind NAT using http tunneling. Is it possible? What all setup is needed to achieve this (like http proxy server etc.)? Is there any library or sample code available for implementing http tunneling over TCP in C#? 回答1: It might be possible for you to use this library: http://granados.sourceforge.net/ It supports port forwarding (tunneling in this case), but I haven't tried it myself. It's an SSH library... so if you can set up an SSH server on

问题 I'm trying to connect my computer to both sides of a NAT (run by OpenWRT) and to establish a TCP connection through the NAT: I run a DHCP server on my first NIC (eth0, ip address 129.104.0.1) and connect it to the WAN port of the router (ip address 129.104.0.198) I connect my wifi (wlan0, ip address 192.168.1.119) to the router's SSID behind the NAT I'm using python and the SO_BINDTODEVICE option to send packet between a server (on eth0) and a client (on wlan0) through the NAT: For the server

问题 Background: I'm trying to setup a VPN server on android phone. For, this I am trying to use android sample application ToyVpn. To setup the server, I have to add following rule in the nat table #Pick a range of private addresses and perform NAT over eth0. iptables -t nat -A POSTROUTING -s 10.0.0.0/8 -o eth0 -j MASQUERADE But I got following error: iptables v1.4.14: can't initialize iptables table -nat: Table does not exist (do you need to insmod?) Perhaps iptables or your kernel needs to be

问题 According to: https://en.wikipedia.org/wiki/Network_address_translation there are 4 types of NAT configurations: Full-cone, Address restricted, Port restricted, and Symmetric. Now, suppose we have client A and client B on separate networks and are hidden behind their own separate NATs. What combinations of "client A NAT type" + "client B NAT type" would require a TURN server to be involved (i.e. not solvable by the STUN protocol) if they want to p2p communicate? For example, I would suspect:

问题 I've successfully made a TURN request to coturn server (https://github.com/coturn/coturn), but failed when executing a STUN request. If I try to STUN connect to coturn server from the same machine running the server using turnutils_stunclient myIP, the server responds with RFC 5780 response 1 0: IPv4. Response origin: : IP1:3478 0: IPv4. Other addr: : IP2:3479 0: IPv4. UDP reflexive addr: IP1:36457 ======================================== RFC 5780 response 2 0: IPv4. Response origin: : IP2

问题 Can someone explain to me what actually happens in the back-end to the load balancer (v2) for the two scenarios: Applying Inbound NAT rules. Applying Load Balancing Rules. 回答1: You would use NAT rule when you have 1 backend server or you know which backend server to get to and loadbalancing rule when you want to loadbalance to multiple backend servers. 回答2: NAT rule must be explicitly attached to a VM (or network interface) to complete the path to the target; whereas Load Balancing rule need