I use QT5.6.3 on MACOS10.15.
I have two ethernet interface. One is en0 , another one is en6. the en0's IP is 192.168.10.199, the en6'IP is 192.168.1.123.
Now I need to receive multicast from en0 .the multicast group address 239.255.255.251 , the multicast port is 47810.
Here is my simplified code:
groupAddress = QHostAddress("239.255.255.251");
QNetworkInterface _interface = QNetworkInterface::interfaceFromName("en6");
udpSocket = new QUdpSocket(this);
udpSocket->bind(QHostAddress::AnyIPv4, 47810, QUdpSocket::ShareAddress|QUdpSocket::ReuseAddressHint );
//I am sure the _interface is en6
udpSocket->setMulticastInterface(_interface);
udpSocket->joinMulticastGroup(groupAddress,_interface));
But, I use netstat command , I find the en0 join the multicast group, not my designated en6
IPv4 Multicast Group Memberships
Group Link-layer Address Netif
224.0.0.251 <none> lo0
224.0.0.1 <none> lo0
**239.255.255.251 1:0:5e:7f:ff:fb en0**
224.0.0.1 1:0:5e:0:0:1 en0
224.0.0.251 1:0:5e:0:0:fb en0
224.0.0.251 1:0:5e:0:0:fb en6
224.0.0.1 1:0:5e:0:0:1 en6
How can I let en6 join the multicast group .It like joinMulticastGroup by interface don't work .
Please help me ,thanks.
It's Qt5.6.3's bug.
This bug is fixed in 5.11 or later.
Related
For debugging purpose I need to set up a MITM proxy between 2 devices.
All devices have static IP (example) and are directly connected each other:
Device 1 : 192.168.10.50
Device 2 : 192.168.10.60
Proxy computer have 2 nic on the same subnet and is between other devices :
D1 .50 <=> [.60 PROXY .50] <=> D2 .60
My problem is, from the proxy if one of the 2 nic is disabled, D1 or D2 can reach the proxy.
Once I bring up the 2 nic, no one can see any other device.
D1 and D2 ip can't be changed.
Proxy is linux centos 8.
Already tested :
adding log on iptables : if 2 nic are up no more input / output log
Drop all input / output then accept only right ip from right interface => no result
Changing arp_filter = 1 and arp_announce = 2 => no result
Testing multiple SO post about 2 nic on same subnet
If anyone can help.
Thanks .
I've found a solution which consist in creating a transparent proxy and intercept some packets.
1- Create a bridge with the 2 NIC :
nmcli connection add type bridge autoconnect yes con-name "br0" ifname "br0"
nmcli connection modify "br0" ipv4.addresses "192.168.10.10/24" ipv4.method manual
nmcli connection delete enp0s3
nmcli connection delete enp0s8
nmcli connection add type bridge-slave autoconnect yes con-name enp0s3 ifname enp0s3 master br0
nmcli connection add type bridge-slave autoconnect yes con-name enp0s8 ifname enp0s8 master br0
2 Add correct rules to intercept specific traffic
nft add table bridge mitm
nft add chain bridge mitm filter { type filter hook prerouting priority 0\; }
nft add rule bridge mitm filter tcp dport 10000 ip saddr 192.168.10.50 meta pkttype set host ether daddr set xx:xx:xx:xx:xx:xx # br0 mac address
nft add rule ip nat PREROUTING tcp dport 10000 ip saddr 192.168.10.50 dnat to 192.168.10.10
It worked for me.
My device is running on Debian OS strech version (not desktop).
I am not an IT personal, but a programmer. I need to know how to configure the network on the debian so both PPP cellular modem & the ethernet interface can access the internet.
There are 3 network interfaces:
1. Ethernet interface enp1s0: dhcp client. (gets ip from the dhcp server and access to the internet)
2. Ethernet interface snp2s0: static ip
3. Modem PPP: wvdial gets access to the internet using the modem
/etc/network/interface file:
auto lo
iface lo inet loopback
allow-hotplug enp1s0
iface enp1s0 inet dhcp
auto enp2s0
iface enp2s0 inet static
address 10.0.13.1
netmask 255.0.0.0
manual ppp0
iface ppp0 inet wvdial
ip route
default via 10.0.0.100 dev enp1s0
10.0.0.0/24 dev enp1s0 proto kernel scope link src 10.0.0.11
10.0.0.0/8 dev enp2s0 proto kernel scope link src 10.0.13.1
/etc/resolv.conf file:
domain mydomain.local
search mydomain.local
nameserver 10.0.0.3
/etc/wvdial.conf file:
[Dialer Defaults]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0
Init3 = AT+CGDCONT=1,"IP","internetg"
Init4 = AT+CGATT=1
Phone = *99***1#
Modem Type = USB Modem
Baud = 460800
New PPPD = yes
Modem = /dev/ttyACM2
ISDN = 0
Password = ''
Username = ''
Auto DNS = Off
/etc/ppp/peers/wvdial file:
noauth
name wvdial
usepeerdns
Problem:
1. My device is running and enp1s0 is connected to the internet. (modem is down)
2. I then run command to perform dialup of the ppp: ifup ppp0
3. As a result the device ppp0 appears in the 'ip a' command, but the ethernet interface enp1s0 is not connected to the internet anymore and also the modem is not connected, but has ip which means there is some problem with routing table and/or dns.
After dialup the ip route table does not have any default/rule for the PPP.
ip route:
default via 10.0.0.100 dev enp1s0
10.0.0.0/24 dev enp1s0 proto kernel scope link src 10.0.0.11
10.0.0.0/8 dev enp2s0 proto kernel scope link src 10.0.13.1
After dialup I noticed that the /etc/resolv.conf file changed and the dns of the ethernet interface is deleted and now appears the PPP dns entries:
/etc/resolv.conf
nameserver 194.90.0.11
nameserver 212.143.0.11
domain mydomain.local
search mydomain.local
The network should behave as follows:
1. If both PPP and ethernet interface are up, then both should have access to the internet at the same time
2. If only 1 of the devices are up (PPP or ethernet interface) then it should work
3. Dialup/Dialdown should not affect the ethernet connection to the internet
What are the exact commands needed and file configuration in order to be able to have PPP and ethernet interface enp1s0 work at the same time?
- ip routing table
- dns
- wvdial
for default route, add defaultroute and replacedefaultroute option to /etc/ppp/peers/wvdial file.
How to get connected machine's IP and Mac of SNMP device.
ARP cache is not giving correct details.
Example for Linux shell commands (no tag for other languages or Windows at time of writing)
Providing that the machine you want to query does run a SNMP Daemon ( generally snmpd from Net-SNMP under Linux ) and that you know how/are allowed to speak to it ( version 1, 2c or 3 with various community names or usernames/passwords/encoding for v3 ) you may issue the following SNMP requests:
For the test I started a snmpd on a CentOS 7 virtual machine whose main address was 192.168.174.128.
I choose port 1610 over the traditional 161 in order not to sudo or to setcap (snmpd). The snmpd.conf file contents is out of the range of this question.
This first one for IPs
snmptable -v 2c -c private 192.168.174.128:1610 ipAddrTable
SNMP table: IP-MIB::ipAddrTable
ipAdEntAddr ipAdEntIfIndex ipAdEntNetMask ipAdEntBcastAddr ipAdEntReasmMaxSize
127.0.0.1 1 255.0.0.0 0 ?
192.168.122.1 3 255.255.255.0 1 ?
192.168.174.128 2 255.255.255.0 1 ?
The second command (with 3 columns only printed) for MAC
snmptable -v 2c -c private 192.168.174.128:1610 ifTable | awk -c '{print $1 "\t" $2 "\t\t" $6}'
SNMP table:
ifIndex ifDescr ifPhysAddress
1 lo up
2 ens33 0:c:29:53:aa:c6
3 virbr0 52:54:0:e6:6b:2f
4 virbr0-nic 52:54:0:e6:6b:2f
When we check under CentOS 7 we get
ifconfig
ens33: ... mtu 1500
inet 192.168.174.128 netmask 255.255.255.0 broadcast 192.168.174.255
inet6 ...
ether 00:0c:29:53:aa:c6 netmask 255.0.0.0
...
lo: ... mtu 65536
inet 127.0.0.1
...
virbr0: ... mtu 1500
inet 192.168.122.1 netmask 255.255.255.0 broadcast 192.168.122.255
ether 52:54:00:e6:6b:2f ...
...
Bonus shell command:
snmptranslate -Oaf IF-MIB::ifTable
.iso.org.dod.internet.mgmt.mib-2.interfaces.ifTable
and
snmptranslate -Oaf IP-MIB::ipAddrTable
.iso.org.dod.internet.mgmt.mib-2.ip.ipAddrTable
I do not know why/if there is a single table holding both information.
Settings in /etc/network/interfaces seems to have no effect on my BeagleBone Black Version C. I want to set my beaglebone black's ethernet IP address to a static IP as I have done with all my other internet-of-things devices running Debian. I edited /etc/network/interfaces as I have before, but I do not see any changes via ifconfig. This is after a restart of networking AND a restart of the beaglebone. I have googled somewhat, and posted to the beaglebone forums after searching them, and I still do not have a solution. I noticed a commented line in interfaces suggesting that the settings are set via an init script, but this is where I get a little lost. I have moderate knowledge of Debian, but I have not peeled back enough layers apparently. I am connecting my beaglebone black via ethernet connector. WIFI is a beast I will tackle later.
I set my router to reserve a specific IP based on MAC ID, but I would like to know what I am missing here.
iface usb0 inet static
address 192.168.0.103
netmask 255.255.255.0
network 192.168.0.0
gateway 192.168.0.1
iface eth0 inet static
address 192.168.0.102
netmask 255.255.255.0
network 192.168.0.0
gateway 192.168.0.1
You are missing the auto line
auto eth0
iface eth0 inet static
address 192.168.0.102
netmask 255.255.255.0
network 192.168.0.0
gateway 192.168.0.1
(Just for diagnosis) - Also remove the gateway line from it
and after you get the connection run this command to add the gateway
root prompt :) #
route add default gateway 192.168.0.1
i was playing around a lot with networking on it so i got the answer. Hope this resolve your issue do post.
Do the configurations in wicd. Run "wicd-client" which opens GUI to make the configuration. Apparently wicd configurations overwrite what you do in /etc/network/interfaces
Another alternative to setting the ipaddress to be static on boot. Even without a ethernet jack plugged in, which was my issue.
Caution: this is hacky, and there probably better streamlined approach
Edit the /opt/scripts/boot/autoconfigure_usb0.sh script
line 92 and 139 set the usb0 default ipaddress
/sbin/ifconfig usb0 ${deb_usb_address} netmask ${deb_usb_netmask} || true
insert the following line after it, in both places
/sbin/ifconfig usb0 ${deb_usb_address} netmask ${deb_usb_netmask} || true
/sbin/ifconfig eth0 192.168.0.123 netmask 255.255.255.0 || true
then it will boot up with that as the static IP address even if you don't have anything plugged it.
I am experimenting with openflow on a setup on emulab. Emulab is a testbed for network experimentation.
I have the following topology. I have 4 regular PC machines, hosta, hostb, switch, and controller.
hosta, hostb, and controller are connected by a gigabit lan to switch. Switch has eth0 for internet connectivity and eth4-6 for all the other hosts. IP addresses follow this sort of pattern, eth4 10.10.1.x, eth5 10.10.2.x and so on.
I am basically following this guide http://geni-app-developer-documentation.readthedocs.org/en/latest/examples/example-3.html
Here is my problem, the guide says that i should create two diffrent bridge interfaces using openvswitch br-int and br-int1. Then procedes to set br-int to request flows from the controller. This makes no sense to me for three reasons.
1) br-int1 should also be requesting from the controller.
2) It seems to me that a bridge interface in this guide is really a swtich, and there should only be one switch and hence only be one bridge interface that includes all the eth4-6 as ports.
3) If the switch really is just "one" switch rather than multiple switches, Than endhosta and endhostb should have IP adresses of this sort, 10.10.a.1 and 10.10.a.2 where a is the same.
I figured it out,
The correct method is this.
ovs-vsctl add-br br0
ovs-vsctl add-port br0 eth4
ovs-vsctl add-port br0 eth5
ovs-vsctl add-port br0 eth6
ifconfig eth4 0
ifconfig eth5 0
ifconfig eth6 0
ifconfig br0 10.10.10.1 netmask 255.255.255.0
route add -net 10.10.10.0 netmask 255.255.255.0 dev br0
now in each of the three remaining nodes run the following command.
ifconfig eth 10.10.10.a
Where is the and a is a unique number.