[jboss-jira] [JBoss JIRA] (JGRP-1880) UDP.ip_ttl is ignored and is always 1
[
https://issues.jboss.org/browse/JGRP-1880?page=com.atlassian.jira.plugin....
]
Bela Ban commented on JGRP-1880:
--------------------------------
I could use reflection, but that's not nice:
{code:java}
DatagramSocket sock=new DatagramSocket(7500);
Method getImpl=sock.getClass().getDeclaredMethod("getImpl");
getImpl.setAccessible(true);
DatagramSocketImpl impl=(DatagramSocketImpl)getImpl.invoke(sock);
System.out.println("impl = " + impl);
Method setTimeToLive=impl.getClass().getDeclaredMethod("setTimeToLive",
int.class);
Method
getTimeToLive=impl.getClass().getDeclaredMethod("getTimeToLive");
getTimeToLive.setAccessible(true);
setTimeToLive.setAccessible(true);
int ttl=0;
ttl=(int)getTimeToLive.invoke(impl);
System.out.println("ttl = " + ttl);
ttl=5;
setTimeToLive.invoke(impl, ttl);
ttl=(int)getTimeToLive.invoke(impl);
System.out.println("ttl = " + ttl);
byte[] buf={'B', 'e', 'l', 'a'};
DatagramPacket packet=new DatagramPacket(buf, 0, buf.length,
InetAddress.getByName("228.8.8.8"), 7500);
sock.send(packet);
{code}
UDP.ip_ttl is ignored and is always 1
-------------------------------------
Key: JGRP-1880
URL: https://issues.jboss.org/browse/JGRP-1880
Project: JGroups
Issue Type: Bug
Reporter: Bela Ban
Assignee: Bela Ban
Fix For: 3.6
Since we switched from using a {{MulticastSocket}} for sending of multicast packets to a
{{DatagramSocket}}, the time-to-live (TTL) of a packet is always {{1}}. The reason is that
method {{setTimeToLive()}} only exists in {{MulticastSocket}}, but not in
{{DatagramSocket}}.
We cannot revert the code and use a {{MulticastSocket}} to send multicasts, as this
won't reveal the real IP address of the sender, but only the multicast address, and
the real address is needed to drop packets at the _transport level_.
Investigate whether we could use reflection to get the {{DatagramSocketImpl}} and call
{{setTimeToLive()}}.
--
This message was sent by Atlassian JIRA
(v6.3.1#6329)