IPv6 UDP server not accepting packets with global address
Hi All,
I am running a IPv6 UDP server, which is bound to in6addr_any. When I send a packet from a client to the link-local address of any interface on the linux box, the server accepts the packets. But when I send the packets to the global address the server doesnt pick the packets.
On snooping I can see that the packets are reaching the interface.
I have tried with following global address 3ffe:x:x::x and 2001:db8:x:x:: addresses assigned to interface.
I checked the statistics and the Recv-Q seems to increment.
When I do simple nslookup it does not generate any query for IPV6 (AAAA). But sometimes I see DNS query for both A and AAAA are generated. What decides this? The reason I do not want AAAA query is in most of the cases AAAA records are absent. Hence, if one DNS server fails, the clients keeps... (1 Reply)
I want to find out the DHCPv6 server's ip address in the network. I went through the lease files but could find only duid/server-id and not the IPv6 address of the dhcp server. And I couldn't find any commands to get that information. Is there a way to get the DHCPv6 server's IPv6 address?
... (0 Replies)
Hi All,
Would anyone know how to modify the below, so only the IPv6 address (red) is printed, please?
(in other words, what's between inet6 and the / sign)
ipv6=`/sbin/ifconfig lo0:5 inet6 | grep 'inet6'`
print $ipv6
Currently the output of the above script is:
inet6... (7 Replies)
Hi,
Am using FreeBSD7.4/i386
During IPv6 configuration, I added the following in rc.conf as
Restarted IPv6 network using /etc/rc.d/network_ipv6 restart..
My problem is I need to set link local IPv6 address auto-configured..
Is my proceeding right??
I feel something missing to make... (0 Replies)
I am looking for an iptables command to allow incoming UDP packets for my Linux server
also is there a command I can use to set the default action for outgoing packets to accept?
Thank you (1 Reply)
How do I configure site-local IPv6 address in HP-UX box?
I can get link local IPv6 address automatically when I put IPv6 up.
aps39-88-root# ifconfig lan0 inet6 up (0 Replies)
Hi all ,
I have a string in my weblog xheader v6-day-2011:xx:yy:zz:qq:qq:ww:ee:rr
My requirement is to lookup the sting v6-day-2011 in this header and if found would like to extract the V6 ip part .
v6-day-2011 is always constant for a ipv6 entry so i would like to extract every thing... (4 Replies)
Hi,
inspired by this article, I decided to implement IPMP + IPv6 in Solaris 10.
It worked for me only this way:
1. Setup
# cat /etc/hostname*
10.23.10.113/24 broadcast + group data failover up <- hostname.e1000g0
0.0.0.0/24 broadcast + group data -failover deprecated up standby... (3 Replies)
I know there is a function inet_tpon for unix platforms to validate ipv6 addresses.But i need an equivalent of windows.When i use this function with the header file <winsock2.h> the visual studio 2005 on win2003 issues an error saying identifier not found
:confused: (3 Replies)
Hello,
I am currently trying to limit incoming UDP length 20 packets on a per IP basis to 5 a second using IPTables on a Linux machine (CentOS 5.2).
Basically, if an IP is sending more than 5 length 20 UDP packet a second to the local machine, I would like the machine to drop the excess... (1 Reply)
UDPTunnel(1) net UDPTunnel(1)NAME
udptunnel - Tunnel UDP packets over a TCP connection
SYNTAX
udptunnel -s TCP-port [-r] [-v] UDP-addr/UDP-port[/ttl]
udptunnel -c TCP-addr[/TCP-port] [-r] [-v] UDP-addr/UDP-port[/ttl]
DESCRIPTION
UDPTunnel is a small program which can tunnel UDP packets bi-directionally over a TCP connection. Its primary purpose (and original motiva-
tion) is to allow multi-media conferences to traverse a firewall which allows only outgoing TCP connections.
USAGE
UDPTunnel can be run in two modes: a client mode and a server mode. The client mode initiates the TCP connection before relaying UDP; the
server waits for an incoming connection before doing so. After the TCP connection is established, the behavior of the two modes is identi-
cal. If you are using UDPTunnel to traverse a firewall as discussed above, the client would be run inside the firewall, and the server
would be run outside it.
OPTIONS -s TCP-port
Server mode: If udptunnel is invoked with the -s option, it runs in server mode: the server will wait for an incoming connection on
the specified TCP port, and then relay UDP to and from it."
-c TCP-addr[/TCP-port]
Client mode: If udptunnel is invoked with the -c option, it runs in client mode: it will open a TCP connection to the specified TCP
host and port, and then relay UDP on it. The TCP port may be omitted in this case; it will default to the same port number as the
UDP port.
-r RTP mode: In order to facilitate tunneling both RTP and RTCP traffic for a multi-media conference, this sets up relays on two con-
secutive TCP and UDP ports. All specified port numbers in this case must be even. Note that both the client and the server must use
the -r flag for this to work; the server will not begin relaying packets until both its connections have been established.
-v Verbose output: This flag turns on verbose debugging output about UDPTunnel's actions. It may be given multiple times. With a single
-v, information about connection establishment is printed on UDPTunnel's standard error stream; with a second one, per-packet infor-
mation is also shown. Note that this latter case can produce a prodigious amount of information. If this flag is not given, UDPTun-
nel will remain silent unless an error occurs.
One of the two options -c and -s must be given; if not, it is an error.
In all cases, the UDP address and port to tunnel is given after all options. UDPTunnel will listen to this adddress for packets, and will
send received packets on this address. The address may be a multicast address; in this case, a multicast TTL should be specified, and tun-
neled packets will be sent with this TTL. All addresses, TCP and UDP, may be specified either as an IPv4 dotted-quad address (e.g.
224.2.0.1) or as a host name (e.g. conrail.cs.columbia.edu). Port numbers must be in the range of 1 to 65535; TTLs must be in the range 0
to 255.
PACKET FORMAT
The packets are sent on TCP using the obvious, simple format: a sixteen-bit length field, in network byte order, precedes each data packet.
This format was proposed in early drafts of RTP for RTP-over-TCP, but was dropped from the final specification.
KNOWN BUGS /ISSUES
UDPTunnel does not check incoming UDP packets to verify that they are indeed coming from the address which the user specified; it binds to
INADDR_ANY, and accepts any UDP packet arriving on the specified port. This could potentially allow denial-of-service or spoofing attacks.
If two or more -v options are given, per-packet identification will be printed of each packet's source address as it is received, allowing
such a situation to be diagnosed.
For multicast, UDPTunnel turns off packet loopback, as it has no way to distinguish its own packets it sent out from packets genuinely
arriving on the multicast group. This means that if you are tunneling traffic from or to a multicast group, both ends of UDPTunnel must be
run on different hosts than any member of the group. (In general, the only way to distinguish looped packets from packets genuinely
received from other applications on the local host is with application-layer labeling, as RTP does.)
UDPTunnel is designed to tunnel RTP-style traffic, in which applications send and receive UDP packets to and from the same port (or pair of
ports). It does not support request/response-style traffic, in which a client request is sent from a transient port X to a well-known port
Y, and the server's response is returned from port Y to port X.
UDPTunnel deliberately ignores "Connection Refused" errors on the UDP port, clearing the socket error state, so that a tunnel may be set up
before conferencing tools are started on both ends. This may mean that a mis-typed UDP address or port is not recognized, as no error is
printed. If two or more -v options are given, a diagnostic will be printed whenever the error state is cleared from the socket.
Once one endpoint of a tunnel is taken down, closing the socket, the other one exits as well; to re-establish the tunnel, UDPTunnel must be
restarted on both sides.
IP version 6 is not supported.
AUTHORS
UDPTunnel was written by Jonathan Lennox <lennox@cs.columbia.edu>. It incorporates code written by Henning Schulzrinne <hgs@cs.colum-
bia.edu>.
This manual page was written by Thomas Scheffczyk <thomas.scheffczyk@verwaltung.uni-mainz.de>, for the Debian GNU/Linux system (but may be
used by others).
Jonathan Lennox 1.1 UDPTunnel(1)