Root squash is a special mapping of the remote superuser (root) identity when using identity authentication (local user is the same as remote user). Under root squash, a client’s uid 0 (root) is mapped to 65534 (nobody). It is primarily a feature of NFS but may be available on other systems as well.
What is no root squash?
No root-squash means that the root user will not be mapped to user nobody (this is normally done for security reasons) when mounting / accessing a NFS file system.
What does No_root_squash mean?
no_root_squash – Allows root users on client computers to have root access on the server. Mount requests for root are not be mounted to the anonomous user. This option is needed for diskless clients.
What are three levels of security in Linux?
For each level of access control (user, group, other), the 3 bits correspond to three permission types. For regular files, these 3 bits control read access, write access, and execute permission. For directories and other file types, the 3 bits have slightly different interpretations.
What is No_all_squash?
all_squash: Map all uids and gids to the anonymous user. Useful for NFS-exported public FTP directories, news spool directories, etc. The opposite option is no_all_squash, which is the default setting. … This option is primarily useful for PC/NFS clients, where you might want all requests appear to be from one user.
What is ETC export Linux?
The /etc/exports file controls which file systems are exported to remote hosts and specifies options. Blank lines are ignored, comments can be made by starting a line with the hash mark ( # ), and long lines can be wrapped with a backslash ( ).
What is Exportfs in Linux?
exportfs stands for export file system, which exports file system to a remote server which can mount, and access it like a local file system. You can also unexport the directories using exportfs command.
How do I view NFS exports?
Viewing the Exported NFS and CIFS Shares
- To view the list of exported NFS and CIFS shares on the 3DFS server, on the command line, enter the following command: # showmount -e.
- To view the list of exported NFS and CIFS shares on the NFS-Ganesha server, on the command line, enter the following command: # ganesha_mgr show_exports.
What is NFS export?
NFS is the most common protocol for sharing files between Unix systems over a network. NFS servers export directories from their local hard disks to NFS clients, which mount them so that they can be accessed like any other directory.
How do I find the Fsid in Linux?
1 Answer. You can use the mountpoint command. The -d switch prints the major/minor device number of the mount point to stdout.
Can Linux be hacked?
The clear answer is YES. There are viruses, trojans, worms, and other types of malware that affect the Linux operating system but not many. Very few viruses are for Linux and most are not of that high quality, Windows-like viruses that can cause doom for you.
What is Linux security model?
Linux Security Modules (LSM) is a framework that allows the Linux kernel to support a variety of computer security models while avoiding favouritism toward any single security implementation. … AppArmor, SELinux, Smack, and TOMOYO Linux are the currently accepted modules in the official kernel.
What is the firewall in Linux?
Firewalls create a barrier between a trusted network (like an office network) and an untrusted one (like the internet). Firewalls work by defining rules that govern which traffic is allowed, and which is blocked. The utility firewall developed for Linux systems is iptables.
What is Nfsnobody?
nfsnobody is the ‘System Account’ that manages all of the anonymous files created by NFS clients.
What is No_subtree_check?
no_subtree_check This option disables subtree checking, which has mild security implications, but can improve reliability in some circumstances.
What is the default port number used by Nfsd daemon in nfsv4?
nfsd listens on TCP and UDP port 2049. It is also the default port number and it doesn’t require special configuration. These five ports should be configured to be fixed to avoid rpcbind assign random port for it.