1bbf21555SRichard Lowe.\" 2bbf21555SRichard Lowe.\" This file and its contents are supplied under the terms of the 3bbf21555SRichard Lowe.\" Common Development and Distribution License ("CDDL"), version 1.0. 4bbf21555SRichard Lowe.\" You may only use this file in accordance with the terms of version 5bbf21555SRichard Lowe.\" 1.0 of the CDDL. 6bbf21555SRichard Lowe.\" 7bbf21555SRichard Lowe.\" A full copy of the text of the CDDL should have accompanied this 8bbf21555SRichard Lowe.\" source. A copy of the CDDL is also available via the Internet at 9bbf21555SRichard Lowe.\" http://www.illumos.org/license/CDDL. 10bbf21555SRichard Lowe.\" 11bbf21555SRichard Lowe.\" 12bbf21555SRichard Lowe.\" Copyright 2015 Joyent, Inc. 13bbf21555SRichard Lowe.\" 14*c55633c3SPeter Tribble.Dd March 30, 2022 15bbf21555SRichard Lowe.Dt OVERLAY 7 16bbf21555SRichard Lowe.Os 17bbf21555SRichard Lowe.Sh NAME 18bbf21555SRichard Lowe.Nm overlay 19bbf21555SRichard Lowe.Nd Overlay Devices 20bbf21555SRichard Lowe.Sh DESCRIPTION 21bbf21555SRichard LoweOverlay devices are a GLDv3 device that allows users to create overlay 22bbf21555SRichard Lowenetworks that can be used to form the basis of network virtualization 23bbf21555SRichard Loweand software defined networking. 24bbf21555SRichard LoweOverlay networks allow a single physical network, often called an 25bbf21555SRichard Lowe.Sy underlay 26bbf21555SRichard Lowenetwork, to provide the means for creating multiple logical, isolated, 27bbf21555SRichard Loweand discrete layer two and layer three networks on top of it. 28bbf21555SRichard Lowe.Pp 29bbf21555SRichard LoweOverlay devices are administered through 30bbf21555SRichard Lowe.Xr dladm 8 . 31bbf21555SRichard LoweOverlay devices themselves cannot be plumbed up with 32bbf21555SRichard Lowe.Sy IP , 33bbf21555SRichard Lowe.Sy vnd , 34bbf21555SRichard Loweor any other protocol. 35bbf21555SRichard LoweInstead, like an 36bbf21555SRichard Lowe.Sy etherstub , 37bbf21555SRichard Lowethey allow for VNICs to be created on top of them. 38bbf21555SRichard LoweLike an 39bbf21555SRichard Lowe.Sy etherstub , 40bbf21555SRichard Lowean overlay device acts as a local switch; however, when it encounters a 41bbf21555SRichard Lowenon-local destination address, it instead looks up where it should send 42bbf21555SRichard Lowethe packet, encapsulates it, and sends it out another interface in the 43bbf21555SRichard Lowesystem. 44bbf21555SRichard Lowe.Pp 45bbf21555SRichard LoweA single overlay device encapsulates the logic to answer two different, 46bbf21555SRichard Lowebut related, questions: 47bbf21555SRichard Lowe.Pp 48bbf21555SRichard Lowe.Bl -enum -offset indent -compact 49bbf21555SRichard Lowe.It 50bbf21555SRichard LoweHow should a packet be transformed and put on the wire? 51bbf21555SRichard Lowe.It 52bbf21555SRichard LoweWhere should a transformed packet be sent? 53bbf21555SRichard Lowe.El 54bbf21555SRichard Lowe.Pp 55bbf21555SRichard LoweEach of these questions is answered by a plugin. 56bbf21555SRichard LoweThe first question is answered by what's called an 57bbf21555SRichard Lowe.Em encapsulation plugin . 58bbf21555SRichard LoweThe second question is answered by what's called a 59bbf21555SRichard Lowe.Em search plugin . 60bbf21555SRichard LowePackets are encapsulated and decapsulated using the encapsulation plugin 61bbf21555SRichard Loweby the kernel. 62bbf21555SRichard LoweThe search plugins are all user land plugins that are consumed by the 63bbf21555SRichard Lowevarpd service whose FMRI is 64bbf21555SRichard Lowe.Em svc:/network/varpd:default . 65bbf21555SRichard LoweThis separation allows for the kernel to be responsible for the data 66bbf21555SRichard Lowepath, while having the search plugins in userland allows the system to 67bbf21555SRichard Loweprovide a much more expressive interface. 68bbf21555SRichard Lowe.Ss Overlay Types 69bbf21555SRichard LoweOverlay devices come in two different flavors, one where all packets are 70bbf21555SRichard Lowealways sent to a single address, the other, where the destination of a 71bbf21555SRichard Lowepacket varies based on the target MAC address of the packet. 72bbf21555SRichard LoweThis information is maintained in a 73bbf21555SRichard Lowe.Em target table , 74bbf21555SRichard Lowewhich is independent and unique to each overlay device. 75bbf21555SRichard LoweWe call the plugins that send traffic to a single location, for example 76bbf21555SRichard Lowea single unicast or multicast IP address, a 77bbf21555SRichard Lowe.Sy point to point 78bbf21555SRichard Loweoverlay and the overlay devices that can send traffic to different 79bbf21555SRichard Lowelocations based on the MAC address of that packet a 80bbf21555SRichard Lowe.Sy dynamic 81bbf21555SRichard Loweoverlay. 82bbf21555SRichard LoweThe plugin type is determined based on the type of the 83bbf21555SRichard Lowe.Sy search plugin . 84bbf21555SRichard LoweThese are all fully listed in the section 85bbf21555SRichard Lowe.Sx Plugins and their Properties . 86bbf21555SRichard Lowe.Ss Overlay Destination 87bbf21555SRichard LoweBoth encapsulation and search plugins define the kinds of destinations 88bbf21555SRichard Lowethat they know how to support. 89bbf21555SRichard LoweAn encapsulation plugin always has a single destination type that's 90bbf21555SRichard Lowedetermined based on how the encapsulation is defined. 91bbf21555SRichard LoweA search plugin, on the other hand, can support multiple combinations of 92bbf21555SRichard Lowedestinations. 93bbf21555SRichard LoweA search plugin must support the destination type of the encapsulation 94bbf21555SRichard Lowedevice. 95bbf21555SRichard LoweThe destination may require any of the following three pieces of 96bbf21555SRichard Loweinformation, depending on the encapsulation plugin: 97bbf21555SRichard Lowe.Bl -hang -width Ds 98bbf21555SRichard Lowe.It Sy MAC Address 99bbf21555SRichard Lowe.Bd -filled -compact 100bbf21555SRichard LoweAn Ethernet MAC address is required to determine the destination. 101bbf21555SRichard Lowe.Ed 102bbf21555SRichard Lowe.It Sy IP Address 103bbf21555SRichard Lowe.Bd -filled -compact 104bbf21555SRichard LoweAn IP address is required. 105bbf21555SRichard LoweBoth IPv4 and IPv6 addresses are supported. 106bbf21555SRichard Lowe.Ed 107bbf21555SRichard Lowe.It Sy Port 108bbf21555SRichard Lowe.Bd -filled -compact 109bbf21555SRichard LoweAn IP protocol level (TCP, UDP, SCTP, etc.) port is required. 110bbf21555SRichard Lowe.Ed 111bbf21555SRichard Lowe.El 112bbf21555SRichard Lowe.Pp 113bbf21555SRichard LoweThe list of destination types that are supported by both the search and 114bbf21555SRichard Loweencapsulation plugins is listed in the section 115bbf21555SRichard Lowe.Sx Plugins and their Properties . 116bbf21555SRichard Lowe.Ss varpd 117bbf21555SRichard LoweThe varpd service, mentioned above, is responsible for providing the 118bbf21555SRichard Lowevirtual ARP daemon. 119bbf21555SRichard LoweIts responsibility is conceptually similar to ARP. 120bbf21555SRichard LoweIt runs all instances of search plugins in the system and is responsible 121bbf21555SRichard Lowefor answering the kernel's ARP-like questions for where packets should 122bbf21555SRichard Lowebe sent. 123bbf21555SRichard Lowe.Pp 124bbf21555SRichard LoweThe varpd service, svc:/network/varpd:default, must be enabled for 125bbf21555SRichard Loweoverlay devices to function. 126bbf21555SRichard LoweIf it is disabled while there are active devices, then most overlay 127bbf21555SRichard Lowedevices will not function correctly and likely will end up dropping 128bbf21555SRichard Lowetraffic. 129bbf21555SRichard Lowe.Sh PLUGINS AND PROPERTIES 130bbf21555SRichard LoweProperties fall into three categories in the system: 131bbf21555SRichard Lowe.Bl -enum -offset indent -compact 132bbf21555SRichard Lowe.It 133bbf21555SRichard LoweGeneric properties all overlay devices have 134bbf21555SRichard Lowe.It 135bbf21555SRichard LoweProperties specific to the encapsulation plugin 136bbf21555SRichard Lowe.It 137bbf21555SRichard LoweProperties specific to the search plugin 138bbf21555SRichard Lowe.El 139bbf21555SRichard Lowe.Pp 140bbf21555SRichard LoweEach property in the system has the following attributes, which mirror 141bbf21555SRichard Lowethe traditional 142bbf21555SRichard Lowe.Xr dladm 8 143bbf21555SRichard Lowelink properties: 144bbf21555SRichard Lowe.Bl -hang -width Ds 145bbf21555SRichard Lowe.It Sy Name 146bbf21555SRichard Lowe.Bd -filled -compact 147bbf21555SRichard LoweThe name of a property is namespaced by its module and always structured 148bbf21555SRichard Loweand referred to as as module/property. 149bbf21555SRichard LoweThis allows for both an encapsulation and search plugin to have a 150bbf21555SRichard Loweproperty with the same name. 151bbf21555SRichard LoweProperties that are valid for all overlay devices and not specific to a 152bbf21555SRichard Lowemodule do not generally use a module prefix. 153bbf21555SRichard Lowe.Pp 154bbf21555SRichard LoweFor example, the property 155bbf21555SRichard Lowe.Sy vxlan/listen_ip 156bbf21555SRichard Loweis associated with the 157bbf21555SRichard Lowe.Sy vxlan 158bbf21555SRichard Loweencapsulation module. 159bbf21555SRichard Lowe.Ed 160bbf21555SRichard Lowe.It Sy Type 161bbf21555SRichard Lowe.Bd -filled -compact 162bbf21555SRichard LoweEach property in the system has a type. 163bbf21555SRichard Lowe.Xr dladm 8 164bbf21555SRichard Lowetakes care of converting between the internal representation and a 165bbf21555SRichard Lowevalue, but the type influences the acceptable input range. 166bbf21555SRichard LoweThe types are: 167bbf21555SRichard Lowe.Bl -hang -width Ds 168bbf21555SRichard Lowe.It Sy INT 169bbf21555SRichard LoweA signed integer that is up to eight bytes long 170bbf21555SRichard Lowe.Pq Sy int64_t . 171bbf21555SRichard Lowe.It Sy UINT 172bbf21555SRichard LoweAn unsigned integer that is up to eight bytes long 173bbf21555SRichard Lowe.Pq Sy uint64_t . 174bbf21555SRichard Lowe.It Sy IP 175bbf21555SRichard LoweEither an IPv4 or IPv6 address in traditional string form. 176bbf21555SRichard LoweFor example, 192.168.128.23 or 2001:470:8af4::1:1. 177bbf21555SRichard LoweIPv4 addresses may also be encoded as IPv4-mapped IPv6 addresses. 178bbf21555SRichard Lowe.It Sy STRING 179bbf21555SRichard LoweA string of ASCII or UTF-8 encoded characters terminated with a 180bbf21555SRichard Lowe.Sy NUL 181bbf21555SRichard Lowebyte. 182bbf21555SRichard LoweThe maximum string length, including the terminator, is currently 183bbf21555SRichard Lowe256 bytes. 184bbf21555SRichard Lowe.El 185bbf21555SRichard Lowe.Ed 186bbf21555SRichard Lowe.It Sy Permissions 187bbf21555SRichard Lowe.Bd -filled -compact 188bbf21555SRichard LoweEach property has permissions associated with it, which indicate whether 189bbf21555SRichard Lowethe system considers them read-only properties or read-write properties. 190bbf21555SRichard LoweA read-only property can never be updated once the device is created. 191bbf21555SRichard LoweThis generally includes things like the overlay's encapsulation module. 192bbf21555SRichard Lowe.Ed 193bbf21555SRichard Lowe.It Sy Required 194bbf21555SRichard Lowe.Bd -filled -compact 195bbf21555SRichard LoweThis property indicates whether the property is required for the given 196bbf21555SRichard Loweplugin. 197bbf21555SRichard LoweIf it is not specified during a call to 198bbf21555SRichard Lowe.Sy dladm create-overlay , 199bbf21555SRichard Lowethen the overlay cannot be successfully created. 200bbf21555SRichard LoweProperties which have a 201bbf21555SRichard Lowe.Sy default 202bbf21555SRichard Lowewill use that value if one is not specified rather than cause the 203bbf21555SRichard Loweoverlay creation to fail. 204bbf21555SRichard Lowe.Ed 205bbf21555SRichard Lowe.It Sy Current Value 206bbf21555SRichard Lowe.Bd -filled -compact 207bbf21555SRichard LoweThe current value of a property, if the property has a value set. 208bbf21555SRichard LoweRequired properties always have a value set. 209bbf21555SRichard Lowe.Ed 210bbf21555SRichard Lowe.It Sy Default Value 211bbf21555SRichard Lowe.Bd -filled -compact 212bbf21555SRichard LoweThe default value is an optional part of a given property. 213bbf21555SRichard LoweIf a property does define a default value, then it will be used when an 214bbf21555SRichard Loweoverlay is created and no other value is given. 215bbf21555SRichard Lowe.Ed 216bbf21555SRichard Lowe.It Sy Value ranges 217bbf21555SRichard Lowe.Bd -filled -compact 218bbf21555SRichard LoweValue ranges are an optional part of a given property. 219bbf21555SRichard LoweThey indicate a range or set of values that are valid and may be set for 220bbf21555SRichard Lowea property. 221bbf21555SRichard LoweA property may not declare such a range as it may be impractical or 222bbf21555SRichard Loweunknown. 223bbf21555SRichard LoweFor example, most properties based on IP addresses will not 224bbf21555SRichard Lowedeclare a range. 225bbf21555SRichard Lowe.Ed 226bbf21555SRichard Lowe.El 227bbf21555SRichard Lowe.Pp 228bbf21555SRichard LoweThe following sections describe both the modules and the properties that 229bbf21555SRichard Loweexist for each module, noting their name, type, permissions, whether or 230bbf21555SRichard Lowenot they are required, and if there is a default value. 231bbf21555SRichard LoweIn addition, the effects of each property will be described. 232bbf21555SRichard Lowe.Ss Encapsulation Plugins 233bbf21555SRichard Lowe.Bl -hang -width Ds 234bbf21555SRichard Lowe.It Sy vxlan 235bbf21555SRichard LoweThe 236bbf21555SRichard Lowe.Sy vxlan 237bbf21555SRichard Lowemodule is a UDP based encapsulation method. 238bbf21555SRichard LoweIt takes a frame that would be put on the wire, wraps it up in a VXLAN 239bbf21555SRichard Loweheader and places it in a UDP packet that gets sent out on the 240bbf21555SRichard Loweunderlying network. 241bbf21555SRichard LoweFor more details about the specific format of the VXLAN header, see 242bbf21555SRichard Lowe.Xr vxlan 4P . 243bbf21555SRichard Lowe.Pp 244bbf21555SRichard LoweThe 245bbf21555SRichard Lowe.Sy vxlan 246bbf21555SRichard Lowemodule requires both an 247bbf21555SRichard Lowe.Sy IP address 248bbf21555SRichard Loweand 249bbf21555SRichard Lowe.Sy port 250bbf21555SRichard Loweto address it. 251bbf21555SRichard LoweIt has a 24-bit virtual network ID space, allowing for 252bbf21555SRichard Lowevirtual network identifiers that range from 253bbf21555SRichard Lowe.Sy 0 254bbf21555SRichard Lowe- 255bbf21555SRichard Lowe.Sy 16777215 . 256bbf21555SRichard Lowe.Pp 257bbf21555SRichard LoweThe 258bbf21555SRichard Lowe.Sy vxlan 259bbf21555SRichard Lowemodule has the following properties: 260bbf21555SRichard Lowe.Bl -hang -width Ds 261bbf21555SRichard Lowe.It Sy vxlan/listen_ip 262bbf21555SRichard Lowe.Bd -filled -compact 263bbf21555SRichard LoweType: 264bbf21555SRichard Lowe.Sy IP | 265bbf21555SRichard LowePermissions: 266bbf21555SRichard Lowe.Sy Read/Write | 267bbf21555SRichard Lowe.Sy Required 268bbf21555SRichard Lowe.Ed 269bbf21555SRichard Lowe.Bd -filled 270bbf21555SRichard LoweThe 271bbf21555SRichard Lowe.Sy vxlan/listen_ip 272bbf21555SRichard Loweproperty determines the IP address that the system will accept VXLAN 273bbf21555SRichard Loweencapsulated packets on for this overlay. 274bbf21555SRichard Lowe.Ed 275bbf21555SRichard Lowe.It Sy vxlan/listen_port 276bbf21555SRichard Lowe.Bd -filled -compact 277bbf21555SRichard LoweType: 278bbf21555SRichard Lowe.Sy UINT | 279bbf21555SRichard LowePermissions: 280bbf21555SRichard Lowe.Sy Read/Write | 281bbf21555SRichard Lowe.Sy Required 282bbf21555SRichard Lowe.Ed 283bbf21555SRichard Lowe.Bd -filled -compact 284bbf21555SRichard LoweDefault Value: 285bbf21555SRichard Lowe.Sy 4789 | 286bbf21555SRichard LoweRange: 287bbf21555SRichard Lowe.Sy 0 - 65535 288bbf21555SRichard Lowe.Ed 289bbf21555SRichard Lowe.Bd -filled 290bbf21555SRichard LoweThe 291bbf21555SRichard Lowe.Sy vxlan/listen_port 292bbf21555SRichard Loweproperty determines the UDP port that the system will listen on for 293bbf21555SRichard LoweVXLAN traffic for this overlay. 294bbf21555SRichard LoweThe default value is 295bbf21555SRichard Lowe.Sy 4789 , 296bbf21555SRichard Lowethe IANA assigned port for VXLAN. 297bbf21555SRichard Lowe.Ed 298bbf21555SRichard Lowe.El 299bbf21555SRichard Lowe.Pp 300bbf21555SRichard LoweThe 301bbf21555SRichard Lowe.Sy vxlan/listen_ip 302bbf21555SRichard Loweand 303bbf21555SRichard Lowe.Sy vxlan/listen_port 304bbf21555SRichard Loweproperties determine how the system will accept VXLAN encapsulated 305bbf21555SRichard Lowepackets for this interface. 306bbf21555SRichard LoweIt does not determine the interface that packets will be sent out over. 307bbf21555SRichard LoweMultiple overlays that all use VXLAN can share the same IP and port 308bbf21555SRichard Lowecombination, as the virtual network identifier can be used to tell the 309bbf21555SRichard Lowedifferent overlays apart. 310bbf21555SRichard Lowe.El 311bbf21555SRichard Lowe.Ss Search Plugins 312bbf21555SRichard LoweBecause search plugins may support multiple destinations, they may have 313bbf21555SRichard Lowemore properties listed than necessarily show up for a given overlay. 314bbf21555SRichard LoweFor example, the 315bbf21555SRichard Lowe.Sy direct 316bbf21555SRichard Loweplugin supports destinations that are identified by both an IP address 317bbf21555SRichard Loweand a port, or just an IP address. 318bbf21555SRichard LoweIn cases where the device is created over an overlay that only uses an 319bbf21555SRichard LoweIP address for its destination, then it will not have the 320bbf21555SRichard Lowe.Sy direct/dest_port 321bbf21555SRichard Loweproperty. 322bbf21555SRichard Lowe.Bl -hang -width Ds 323bbf21555SRichard Lowe.It Sy direct 324bbf21555SRichard LoweThe 325bbf21555SRichard Lowe.Sy direct 326bbf21555SRichard Loweplugin is a point to point module that can be used to create an overlay 327bbf21555SRichard Lowethat forwards all non-local traffic to a single destination. 328bbf21555SRichard LoweIt supports destinations that are a combination of an 329bbf21555SRichard Lowe.Sy IP Address 330bbf21555SRichard Loweand a 331bbf21555SRichard Lowe.Sy port . 332bbf21555SRichard Lowe.Pp 333bbf21555SRichard LoweThe 334bbf21555SRichard Lowe.Sy direct 335bbf21555SRichard Loweplugin has the following properties: 336bbf21555SRichard Lowe.Bl -hang -width Ds 337bbf21555SRichard Lowe.It Sy direct/dest_ip 338bbf21555SRichard Lowe.Bd -filled -compact 339bbf21555SRichard LoweType: 340bbf21555SRichard Lowe.Sy IP | 341bbf21555SRichard LowePermissions: 342bbf21555SRichard Lowe.Sy Read/Write | 343bbf21555SRichard Lowe.Sy Required 344bbf21555SRichard Lowe.Ed 345bbf21555SRichard Lowe.Bd -filled 346bbf21555SRichard LoweThe 347bbf21555SRichard Lowe.Sy direct/dest_ip 348bbf21555SRichard Loweproperty indicates the IP address that all traffic will be sent out. 349bbf21555SRichard LoweTraffic will be sent out the corresponding interface based on 350bbf21555SRichard Lowetraditional IP routing rules and the configuration of the networking 351bbf21555SRichard Lowestack of the global zone. 352bbf21555SRichard Lowe.Ed 353bbf21555SRichard Lowe.It Sy direct/dest_port 354bbf21555SRichard Lowe.Bd -filled -compact 355bbf21555SRichard LoweType: 356bbf21555SRichard Lowe.Sy UINT | 357bbf21555SRichard LowePermissions: 358bbf21555SRichard Lowe.Sy Read/Write | 359bbf21555SRichard Lowe.Sy Required 360bbf21555SRichard Lowe.Ed 361bbf21555SRichard Lowe.Bd -filled -compact 362bbf21555SRichard LoweDefault Value: 363bbf21555SRichard Lowe.Sy - | 364bbf21555SRichard LoweRange: 365bbf21555SRichard Lowe.Sy 0 - 65535 366bbf21555SRichard Lowe.Ed 367bbf21555SRichard Lowe.Bd -filled 368bbf21555SRichard LoweThe 369bbf21555SRichard Lowe.Sy direct/dest_port 370bbf21555SRichard Loweproperty indicates the TCP or UDP port that all traffic will be directed 371bbf21555SRichard Loweto. 372bbf21555SRichard Lowe.Ed 373bbf21555SRichard Lowe.El 374bbf21555SRichard Lowe.It Sy files 375bbf21555SRichard LoweThe 376bbf21555SRichard Lowe.Sy files 377bbf21555SRichard Loweplugin implements a 378bbf21555SRichard Lowe.Sy dynamic 379bbf21555SRichard Loweplugin that specifies where traffic should be sent based on a file. 380bbf21555SRichard LoweIt is a glorified version of /etc/ethers. 381bbf21555SRichard LoweThe 382bbf21555SRichard Lowe.Sy dynamic 383bbf21555SRichard Loweplugin does not support broadcast or multicast traffic, but it has 384bbf21555SRichard Lowesupport for proxy ARP, NDP, and DHCPv4. 385bbf21555SRichard LoweFor the full details of the file format, see 386*c55633c3SPeter Tribble.Xr overlay_files 5 . 387bbf21555SRichard Lowe.Pp 388bbf21555SRichard LoweThe 389bbf21555SRichard Lowe.Sy files 390bbf21555SRichard Loweplugin has the following property: 391bbf21555SRichard Lowe.Bl -hang -width Ds 392bbf21555SRichard Lowe.It Sy files/config 393bbf21555SRichard Lowe.Bd -filled -compact 394bbf21555SRichard LoweType: 395bbf21555SRichard Lowe.Sy String | 396bbf21555SRichard LowePermissions: 397bbf21555SRichard Lowe.Sy Read/Write | 398bbf21555SRichard Lowe.Sy Required 399bbf21555SRichard Lowe.Ed 400bbf21555SRichard Lowe.Bd -filled 401bbf21555SRichard LoweThe 402bbf21555SRichard Lowe.Sy files/config 403bbf21555SRichard Loweproperty specifies an absolute path to a file to read. 404bbf21555SRichard LoweThe file is a JSON file that is formatted according to 405bbf21555SRichard Lowe.Xr overlay_files 5 . 406bbf21555SRichard Lowe.Ed 407bbf21555SRichard Lowe.El 408bbf21555SRichard Lowe.El 409bbf21555SRichard Lowe.Ss General Properties 410bbf21555SRichard LoweEach overlay has the following properties which are used to give 411bbf21555SRichard Loweadditional information about the system. 412bbf21555SRichard LoweNone of these properties may be specified as part of a 413bbf21555SRichard Lowe.Sy dladm create-overlay , 414bbf21555SRichard Loweinstead they come from other arguments or from internal parts of the 415bbf21555SRichard Lowesystem. 416bbf21555SRichard Lowe.Bl -hang -width Ds 417bbf21555SRichard Lowe.It Sy encap 418bbf21555SRichard Lowe.Bd -filled -compact 419bbf21555SRichard Lowe.Sy String | 420bbf21555SRichard LowePermissions: 421bbf21555SRichard Lowe.Sy Read Only 422bbf21555SRichard Lowe.Ed 423bbf21555SRichard Lowe.Bd -filled 424bbf21555SRichard LoweThe 425bbf21555SRichard Lowe.Sy encap 426bbf21555SRichard Loweproperty contains the name of the encapsulation module that's in use. 427bbf21555SRichard Lowe.Ed 428bbf21555SRichard Lowe.It Sy mtu 429bbf21555SRichard Lowe.Bd -filled -compact 430bbf21555SRichard Lowe.Sy UINT | 431bbf21555SRichard LowePermissions: 432bbf21555SRichard Lowe.Sy Read/Write 433bbf21555SRichard Lowe.Ed 434bbf21555SRichard Lowe.Bd -filled -compact 435bbf21555SRichard LoweDefault Value: 436bbf21555SRichard Lowe.Sy 1400 | 437bbf21555SRichard LoweRange: 438bbf21555SRichard Lowe.Sy 576 - 9000 439bbf21555SRichard Lowe.Ed 440bbf21555SRichard Lowe.Bd -filled 441bbf21555SRichard LoweThe 442bbf21555SRichard Lowe.Sy mtu 443bbf21555SRichard Loweproperty describes the maximum transmission unit of the overlay. 444bbf21555SRichard LoweThe default value is 445bbf21555SRichard Lowe.Sy 1400 446bbf21555SRichard Lowebytes, which ensures that in a traditional deployment with an MTU of 447bbf21555SRichard Lowe1500 bytes, the overhead that is added from encapsulation is all 448bbf21555SRichard Loweaccounted for. 449bbf21555SRichard LoweIt is the administrator's responsibility to ensure that 450bbf21555SRichard Lowethe device's MTU and the encapsulation overhead does not exceed that of 451bbf21555SRichard Lowethe interfaces that the encapsulated traffic will be sent out of. 452bbf21555SRichard Lowe.Pp 453bbf21555SRichard LoweTo modify the 454bbf21555SRichard Lowe.Sy mtu 455bbf21555SRichard Loweproperty, use 456bbf21555SRichard Lowe.Sy dladm set-linkprop . 457bbf21555SRichard Lowe.Ed 458bbf21555SRichard Lowe.It Sy search 459bbf21555SRichard Lowe.Bd -filled -compact 460bbf21555SRichard Lowe.Sy String | 461bbf21555SRichard LowePermissions: 462bbf21555SRichard Lowe.Sy Read Only 463bbf21555SRichard Lowe.Ed 464bbf21555SRichard Lowe.Bd -filled 465bbf21555SRichard LoweThe 466bbf21555SRichard Lowe.Sy search 467bbf21555SRichard Loweproperty contains the name of the search plugin that's in use. 468bbf21555SRichard Lowe.Ed 469bbf21555SRichard Lowe.It Sy varpd/id 470bbf21555SRichard Lowe.Bd -filled -compact 471bbf21555SRichard Lowe.Sy String | 472bbf21555SRichard LowePermissions: 473bbf21555SRichard Lowe.Sy Read Only 474bbf21555SRichard Lowe.Ed 475bbf21555SRichard Lowe.Bd -filled 476bbf21555SRichard LoweThe 477bbf21555SRichard Lowe.Sy varpd/id 478bbf21555SRichard Loweproperty indicates the identifier which the 479bbf21555SRichard Lowe.Sy varpd 480bbf21555SRichard Loweservice uses for this overlay. 481bbf21555SRichard Lowe.Ed 482bbf21555SRichard Lowe.It Sy vnetid 483bbf21555SRichard Lowe.Bd -filled -compact 484bbf21555SRichard Lowe.Sy UINT | 485bbf21555SRichard LowePermissions: 486bbf21555SRichard Lowe.Sy Read/Write 487bbf21555SRichard Lowe.Ed 488bbf21555SRichard Lowe.Bd -filled 489bbf21555SRichard LoweThe 490bbf21555SRichard Lowe.Sy vnetid 491bbf21555SRichard Loweproperty has the virtual network identifier that belongs to this overlay. 492bbf21555SRichard LoweThe valid range for the virtual network identifier depends on the 493bbf21555SRichard Loweencapsulation engine. 494bbf21555SRichard Lowe.Ed 495bbf21555SRichard Lowe.El 496bbf21555SRichard Lowe.Sh FMA INTEGRATION 497bbf21555SRichard LoweOverlay devices are wired into FMA, the illumos fault management 498bbf21555SRichard Lowearchitecture, and generates error reports depending on the 499bbf21555SRichard Lowe.Sy search 500bbf21555SRichard Loweplugin in use. 501bbf21555SRichard LoweDue to limitations in FMA today, when a single overlay 502bbf21555SRichard Loweenters a degraded state, meaning that it cannot properly perform look 503bbf21555SRichard Loweups or another error occurred, then it degrades the overall 504bbf21555SRichard Lowe.Sy overlay 505bbf21555SRichard Lowepseudo-device driver. 506bbf21555SRichard Lowe.Pp 507bbf21555SRichard LoweFor more fine-grained information about which overlay is actually in a 508bbf21555SRichard Lowe.Em degraded 509bbf21555SRichard Lowestate, one should run 510bbf21555SRichard Lowe.Sy dladm show-overlay -f . 511bbf21555SRichard LoweIn addition, for each overlay in a degraded state a more useful 512bbf21555SRichard Lowediagnostic message is provided which describes the reason that caused 513bbf21555SRichard Lowethis overlay to enter into a degraded state. 514bbf21555SRichard Lowe.Pp 515bbf21555SRichard LoweThe overlay driver is self-healing. 516bbf21555SRichard LoweIf the problem corrects itself on its own, it will clear the fault on 517bbf21555SRichard Lowethe corresponding device. 518bbf21555SRichard Lowe.Sh SEE ALSO 519bbf21555SRichard Lowe.Xr vxlan 4P , 520bbf21555SRichard Lowe.Xr overlay_files 5 , 521bbf21555SRichard Lowe.Xr dladm 8 522