Linux Client Troubleshooting

Resolve Backspace key issues (MobaXterm vs. PuTTY/OpenSSH)

By default, MobaXterm sends ^H (ASCII 0x08, the BS character) when you press Backspace, while PuTTY and OpenSSH clients typically send ^? (DEL, 0x7F). If the client and server don’t agree on which character represents Backspace, you may see ^H printed on screen instead of characters being deleted, or Backspace may not work at all.

Step 1: Choose a fix location

You can resolve the mismatch either on the client (MobaXterm) or on the server. Option A — Client-side (MobaXterm)

Open Settings → Terminal
Disable the “Backspace sends ^H” option
Restart the session

Mobaxterm Session Settings 1 — 'Backspace sends ^H' checkbox in Session settings (MobaXterm)

This makes MobaXterm send ^? instead, matching PuTTY/OpenSSH behavior. Option B — Server-side Run the following command on the server:

stty erase ^H

This tells the server to interpret ^H as the erase/backspace character.

Step 2: Verify the fix

Press Backspace in your terminal session and confirm that characters are deleted correctly and ^H is no longer printed on screen.

If the issue persists after applying one fix, try the other side (client vs. server) — some environments require both settings to align, especially when connecting through intermediate hosts or jump servers.

Log SSH connections through a jump server

When an SSH connection is tunneled through a jump server, the jump host never opens an actual new SSH connection to the target — it just forwards the TCP stream, and that stream stays encrypted end-to-end between the original client and the final target. Because of this, a Syteca Client installed on the jump host can’t monitor tunneled connections, whether the tunnel was opened with the -J flag or by proxying through sshd_config. To monitor these sessions, Syteca must be installed on the target host instead.

Prevent tunneling through the jump host

To stop connections from tunneling through a jump server entirely, add the following to its sshd_config:

AllowAgentForwarding no
AllowTcpForwarding no
PermitTunnel no

Log tunneled connections at the jump host

Alternatively, if the connection is opened as a nested SSH command rather than a true tunnel:

ssh -tt jumpHost "ssh -tt targetHost"

Syteca installed on the jump host logs this as a new connection and monitors its output normally.

Resolve SSH connection delays with mDNS

Configuring mDNS (multicast DNS) on a Linux endpoint lets it resolve other local devices’ hostnames without a central DNS server — which can eliminate the delay some SSH connections experience while the system tries (and fails) to resolve local hostnames without one. Avahi is the most common mDNS implementation for Linux.

Install Avahi

Debian / Ubuntu
RHEL / CentOS

sudo apt-get update
sudo apt-get install avahi-daemon avahi-utils

sudo yum update
sudo yum install avahi-daemon avahi-tools

Enable and start the daemon

sudo systemctl enable avahi-daemon
sudo systemctl start avahi-daemon

Optionally configure the Avahi config file

sudo nano /etc/avahi/avahi-daemon.conf

Relevant settings:

use-ipv4=yes / use-ipv6=yes — enable Avahi on IPv4, IPv6, or both.
allow-interfaces=eth0 — restrict Avahi to specific interfaces.
deny-interfaces=eth1 — exclude specific interfaces.

Restart Avahi

sudo systemctl restart avahi-daemon

Check Avahi's status

sudo systemctl status avahi-daemon

Open the mDNS port in the firewall

Avahi needs UDP port 5353 open:

iptables
firewalld

sudo iptables -A INPUT -p udp --dport 5353 -j ACCEPT
sudo iptables -A OUTPUT -p udp --dport 5353 -j ACCEPT

sudo firewall-cmd --zone=public --add-port=5353/udp --permanent
sudo firewall-cmd --reload

Test hostname resolution

ping <hostname>.local

Replace <hostname> with the target computer’s actual hostname. Names ending in .local should now resolve without further configuration.

Confirm the firewall allows port 5353 with sudo iptables -L INPUT -n --line-numbers | grep :5353 (iptables) or sudo firewall-cmd --list-all | grep 5353 (firewalld). Confirm Avahi itself is working with:

avahi-resolve-host-name -4 -n <hostname>.local

-4 restricts resolution to IPv4 (use -6 for IPv6); -n specifies the hostname to resolve. A returned IP address confirms Avahi and the firewall are both configured correctly.

The Linux Client doesn’t record sessions of non-root users

NOT AVAILABLE IN SAAS.

Check the basics first

Confirm the Linux Client is online with a valid license, and that no filtering parameter or rule excludes the affected users.

Check settings.xml permissions

Run:

ls -l /etc/.ekran/settings.xml

The .ekran folder needs 755 permissions, and settings.xml needs 644.

Check the Client installation folder permissions

Run:

ls -l /opt/.Ekran/

The .Ekran folder and every file inside it need 755 permissions.

Check ld.so.preload permissions

Run:

ls -l /etc/ld.so.preload

This file needs 644 permissions.

Restart the Linux Client

NOT AVAILABLE IN SAAS.

sudo service Ekran restart

Or stop and start it separately:

sudo service Ekran stop
sudo service Ekran start

Ekran (the service name) is a literal system identifier, preserved verbatim from source.

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Overview

FAQ

Troubleshooting

Reference

Linux Client Troubleshooting

Resolve Backspace key issues (MobaXterm vs. PuTTY/OpenSSH)

Step 1: Choose a fix location

Step 2: Verify the fix

Log SSH connections through a jump server

Prevent tunneling through the jump host

Log tunneled connections at the jump host

Resolve SSH connection delays with mDNS

The Linux Client doesn’t record sessions of non-root users

Restart the Linux Client

Linux Clients

Windows Firewall configuration

Client Troubleshooting

Logs

​Resolve Backspace key issues (MobaXterm vs. PuTTY/OpenSSH)

​Step 1: Choose a fix location

​Step 2: Verify the fix

​Log SSH connections through a jump server

​Prevent tunneling through the jump host

​Log tunneled connections at the jump host

​Resolve SSH connection delays with mDNS

​The Linux Client doesn’t record sessions of non-root users

​Restart the Linux Client

​Related

Linux Clients

Windows Firewall configuration

Client Troubleshooting

Logs

Resolve Backspace key issues (MobaXterm vs. PuTTY/OpenSSH)

Step 1: Choose a fix location

Step 2: Verify the fix

Log SSH connections through a jump server

Prevent tunneling through the jump host

Log tunneled connections at the jump host

Resolve SSH connection delays with mDNS

The Linux Client doesn’t record sessions of non-root users

Restart the Linux Client

Related